Special Status Plant Species in the Merced River Corridor Within Yosemite National Park on the COVER: Vernal Slab-Seep Community Near Merced Lake

Home , Antennaria argentea, Asarum hartwegii, Bolandra, Bolandra californica, Carex senta, Ceanothus

National Park Service U.S. Department of the Interior

Natural Resource Program Center

Special Status Plant Species in the Merced River Corridor within Yosemite National Park ON THE COVER: Vernal slab-seep community near Merced Lake. Credits: Photo by Dean Taylor Special Status Plant Species of the Merced River Corridor within Yosemite National Park

Alison E.L. Colwell, PhD Botanist Resources Management and Science Yosemite National Park 5083 Foresta Road El Portal, CA 95318 and

Dean W. Taylor, PhD Consulting Botanist 3212 Redwood Drive Aptos, CA 95003

May 2011

U.S. Department of the Interior National Park Service Yosemite National Park El Portal, California Special Status Plant Species in the Merced River Corridor

The National Park Service, Natural Resource Program Center publishes a range of reports that address natural resource topics of interest and applicability to a broad audience in the National Park Service and others in natural resource management, including scientists, conservation and environmental constituencies, and the public.

[include one of the following two paragraphs, depending on whether it is an NRR or NRTR report]

The Natural Resource Report Series is used to disseminate high-priority, current natural resource management information with managerial application. The series targets a general, diverse audience, and may contain NPS policy considerations or address sensitive issues of management applicability.

The Natural Resource Technical Report Series is used to disseminate results of scientific studies in the physical, biological, and social sciences for both the advancement of science and the achievement of the National Park Service mission. The series provides contributors with a forum for displaying comprehensive data that are often deleted from journals because of page limitations.

All manuscripts in the series receive the appropriate level of peer review to ensure that the information is scientifically credible, technically accurate, appropriately written for the intended audience, and designed and published in a professional manner.

Peer review manager: choose one or combine and edit multiple pieces from the numbered statements below to best describe the type of peer review performed. The result should be in regular paragraph format and the same font and color as all other text on this page. Make sure to delete this paragraph along with all other unwanted text currently shown in blue italic font.

1. This report received informal peer review by subject-matter experts who were not directly involved in the collection, analysis, or reporting of the data. 2. Data in this report were collected and analyzed using methods based on established, peer-reviewed protocols and were analyzed and interpreted within the guidelines of the protocols. 3. This report received formal peer review by subject-matter experts who were not directly involved in the collection, analysis, or reporting of the data, and whose background and expertise put them on par technically and scientifically with the authors of the information. 4. This report received formal, high-level peer review based on the importance of its content, or its potentially con- troversial or precedent-setting nature. Peer review was conducted by highly qualified individuals with subject area technical expertise and was overseen by a peer review manager.

Views, statements, findings, conclusions, recommendations, and data in this report do not necessarily reflect views and policies of the National Park Service, U.S. Department of the Interior. Mention of trade names or commercial products does not constitute endorsement or recommendation for use by the U.S. Government.

This report is available from Your Network/Division etc. and URL and the Natural Resource Publications Management Web site (http://www.nature.nps.gov/publications/NRPM) on the Internet.

Please cite this publication as:

Lastname, A., C. Lastname, and D. Lastname. 20XX. Full title of report in sentence case, including subtitle. Natural Resource [Technical] Report NPS/XXXX/NRXX—20XX/XXX. National Park Service, Fort Collins, Colorado.

Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park.

ii Contents

Executive Summary...... v Acknowledgments...... vi Introduction...... 1 The Drivers of Floristic Diversity and Species Richness in the Region...... 1 Study area...... 3 Effect of Past Human Use...... 3 Effect of Invasive Species on Special Status Plants...... 3 Effect of Climate Warming and Nitrogen Input...... 4 Methods...... 5 Assessment of Prior Knowledge...... 5 Historical Records Reviewed...... 5 Historic Collections not Relocated...... 6 Survey Methods...... 8 Areas Not Surveyed for This Study...... 9 GPS Data Collection and Analysis...... 9 Map Information...... 10 Location of Data and Specimens...... 10 Results & Discussion...... 11 Merced Lake ...... 11 Results of Surveys of Merced Lake...... 11 Discussion of Special Status Species Occurrences...... 11 Notable Trees...... 11 Impacts of Human Activity...... 12 Little Yosemite Valley & Vernal Falls...... 15 Results of Survey from Merced Lake to Happy Isles...... 15 Discussion of Special Status Species Occurrences...... 15 Trampling Impacts...... 17 Candidate Special Status Species...... 18 Special Status Species...... 18 Yosemite Valley...... 20 Results of Yosemite Valley Surveys...... 20 Discussion...... 20 Adverse Impacts: Changed Hydrology...... 22 Impacts of Landscaping on Special Status Species...... 23 Impacts of Invasive Species on Special Status Plants...... 24

iii Special Status Plant Species in the Merced River Corridor

Impacts of Trampling...... 25 Yosemite Valley to El Portal...... 26 Results of Yosemite Valley to El Portal Survey ...... 26 Discussion...... 26 El Portal Administrative Site...... 28 Results of El Portal Surveys...... 28 Discussion...... 28 Wawona...... 32 Results of the Surveys in Wawona...... 32 Discussion ...... 32 Impacts to Special Status Species ...... 33 Bibliography...... 35

Appendix 1 Condition Assessment of Valley Oaks (Quercus lobata) in El Portal...... 37 Background...... 37 Condition at the time of 1987 designation...... 37 Appendix 2 Condition Assessment of Sierra Sweetbay (Myrica hartwegii) in Wawona ...... 40 Existing Documentation...... 41 Current Condition of the Habitat...... 44 Appendix 3 Yosemite Special Status Plants Documented in Merced River Corridor...... 46 Appendix 4 Plant List for Wawona Golf Course...... 50

iv Executive Summary

Executive Summary

Targeted botanical surveys were undertaken in the following areas of high human impact along the Merced River corridor within Yosemite National Park: Merced Lake, Little Yosemite Valley, Yosemite Valley, El Portal and Wawona. The intention of these surveys is to assist the planning process for the Wild and Scenic River designation for the Merced River by filling in gaps in existing knowledge about park special status plant distribution and condition along the river. The overall pattern of special status species occurrence in these areas was found to be primarily in unusual habitat types that are often restricted in size. Unusual habitat types are those typically associated with specific kinds of water abundance, such as waterfall spray zones, braided river channels, oxbow cutoffs, gravelbars resulting from flooding, water seepage on rock walls, vernal pools, and the average high water margin of streams and rivers. The overarching management goal for preserving biodiversity in the Merced River corridor should therefore be 1) to avoid adverse impacts to restricted or unusual habitat types essential to the specialist species that occupy them and 2) to avoid interfering with the natural processes that allow dispersal between, and colonization of, these habitats to occur (e.g., do not exacerbate fragmentation of habitats). The adverse impacts to special status species habitats noted by these surveys: trampling and encroachment by invasive species were primarily.

v Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

Acknowledgments

Thanks to our intrepid field crew members Heather Smith, Josh Higgins, Dan Bracken, Kate Weideman, Andrea Keil, and Shannon Henke for untold miles of bushwhacking and mapping.

Thanks to Erin Babich and Kate Wilkin, who suffered, while creating these maps, the triple calamities of a lemon laptop, the bugs of a new version of ArcGIS and a spring snowstorm that knocked out power for a week.

Thanks to reviewers Lisa Acree, Judi Weaser, Joe Meyer, and Mike Yochim for their helpful comments and discussions on the ideas presented in this report. Thanks to Lisa Acree for the valley oak information included in Appendix 2. Thanks to Michael Park for his comments on the manuscript and help with the mapping of the new species of Collinsia in El Portal.

Thanks to Bruce Ponman for his help editing and formatting this report.

Photos are by the authors unless otherwise noted.

vi Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Introduction

These [mountain torrents] have worn deep and picturesque channels in the granite rocks, and in the moist shadows of their recesses grow tender plants of rare and peculiar loveliness. The broad parachute-like leaves of the peltate saxifrage, delicate ferns, soft mosses, and the most brilliant lichens abound…

– Frederick Law Olmsted, 1865.

From: Yosemite and the Mariposa Grove: A Preliminary Report.

Introduction

The botanical studies described in this and the subset of the species on that list report were undertaken to provide infor- which have been found within 0.5 kilome- mation for the planning process for the ter of the Merced River is Appendix 3. Merced Wild and Scenic River designation. Current data on the location and This report deals with vascular plants only condition of rare plant species associated (ferns, fern allies, conifers, and flowering with the Merced River in developed areas plants). Rare non-vascular plants, such in Yosemite National Park was identified as mosses, liverworts, lichens, and algae, as an information gap. Therefore, surveys also exist in Yosemite, and some occur in targeting five areas (Merced Lake, Little the same locations covered in this report, Yosemite Valley, Yosemite Valley, El Portal but Yosemite does not yet confer ‘special Administrative Site, and Wawona) were status’ on these groups. undertaken in the summer and fall of 2010 and the spring of 2011. This report pres- The Drivers of Floristic Diver- ents results of these survey efforts. This sity and Species Richness in the report also summarizes the state of the Region knowledge of the flora for the surveyed areas as well as the rest of the Merced River The flora of Yosemite National Park has corridor within Yosemite National Park. been recognized as being unusually rich and diverse since scientists began docu- In this report, we will use the term ‘spe- menting it in the 1860s. During the 170 cial status species’ in lieu of the term ‘rare years that the flora has been under scien- species’, because Yosemite recognizes and tific study, over 1600 vascular plant species gives additional protection to species that have been documented in the park (equal- may have wide distribution outside of the ling approximately 8% of the number of park but are rare within the park (Moore species known in the US and Canada.). 2004). This is in addition to recognizing Recently initiated surveys of other plant those listed as rare by federal agencies, the groups are uncovering a similarly rich and State of California, and the California Na- diverse flora for those groups, with over tive Plant Society, the designation ‘special 200 moss and liverwort species, over 600 status species’ therefore includes all rare lichen species and over 400 algae spe- species. cies documented to date. This flora also includes a high percentage of rare species As knowledge of plant distributions and and endemic species (Endemic species are occurrences within Yosemite changes and those occurring only in this region.). the taxonomy of the special status plants changes, the list of officially recognized There are three main drivers generat- special status species must be periodically ing this unusual biodiversity: landscape updated. The special status species list heterogeneity, landscape fragmentation used by these surveys was updated in 2006 and landscape stability. The first driver,

1 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

landscape heterogeneity, has three main the larger than usual number of rare and components. The first component is varia- endemic species found here. tion in topography along the river course. The second component is variation in The third driver of regional biodiversity moisture abundance in the habitats sur- is the great age of the montane habitat. rounding the river. The third component Much of the uplands through which the is the variation in soils, which have differ- two branches of the Merced River flow ent nutrient components, water-retention in Yosemite remained largely free of ice capacities, as well as other unique traits. during recent glacial epochs (Matthes All three components are in large part the 1930; Alpha et al. 1987), and were local result of the presence of multiple substrate refugia to plant species as masses of ice rock types along the river corridor that ground past in the valley bottoms. Colo- vary in their susceptibility to erosion, in nization of the post-glaciation valley bot- the slope stability and steepness in this toms was then a simple matter of gravity- eroding terrain, and to the soil texture and aided short-distance dispersal. Therefore structure generated by erosion and weath- species that may have been more wide- ering of bedrock. Together, these generate spread in previous epochs (giant sequoia an unusually large variety of habitats for is a good example), have been able to plant species specialists. Because of the survive here where climate and topogra- restricted size of many of these habitats phy have remained stable. Furthermore, (e.g., the waterfall spray zone, braided mounting evidence in recent decades river channels, oxbow cutoffs, gravel bars favors a greater age of montane habitat in resulting from periodic flooding, water the south and central Sierra Nevada that seepage on rock walls, vernal pools, and previously thought (Small and Anderson the average high water margin of streams 1995; Wernicke et al. 1996. Others (Stock and rivers), many of the species present at et al. 2004, 2005; Mulch et al. 2006; such sites are necessarily highly restricted House et al. 1998, 2001) have suggested in their ranges. that the region through which the Mer- ced River flows has been mountainous The second driver of regional biodiversity throughout the Cenozoic (65 mya) and is landscape fragmentation, caused pri- possibly since some time in the Meso- marily by the cumulative effects of millions zoic. This means that the cooler, moister of years of erosion and glaciations (Huber montane habitat characteristic of most of 1989; Glazner and Stock 2010). The scale Yosemite has been stably present in this of this in the region is dramatic: erosion region for sufficiently long time periods in combination with mountain uplift has (tens of millions of years) for evolution- carved deep, steep-sided canyons. At the ary processes to have operated in place, same time, from Yosemite Valley up- creating species found only in this region stream, glaciation events have enhanced because they evolved here and have not the process by repeatedly isolating in- yet dispersed elsewhere (Kimball et al. terfluves from each other with masses of 2004). ice, the ice carving ever wider east-west canyons, each time enlarging these already These three landscape factors that are substantial natural barriers to north- important drivers of biodiversity may yet south dispersal of plants and their insect offer refugia for species threatened with pollinators. These chasms have isolated extinction during the current episode of populations of species from each other, rapid climate shift. The presence of het- and prevented many species from track- erogeneous habitats closely juxtaposed ing climate warming and cooling shifts as within the Merced River canyons pres- they normally do by moving up and down ents opportunities for species to disperse in latitude, thereby accelerating extinc- to and colonize nearby newly favorable tions, evolutionary diversification, and sites. The over arching management goal speciation, which today is manifested in for preserving biodiversity in the Mer-

2 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Introduction

ced River corridor should therefore be by cascades, boulders, or woody debris, 1) to avoid impacts to restricted habitat such as fallen trees. types essential to the specialist species that occupy them and 2) to avoid inter- Effect of Past Human Use fering with the natural processes that allow dispersal and colonization to occur The Merced River within Yosemite (e.g., do not exacerbate fragmentation of National Park has supported substantial habitats). human habitation for thousands of years, and the entire length of both rivers in the Study area park continues to be seasonally visited by humans, and is thus entirely affected by The Merced River within Yosemite Na- human use to some extent. The prehis- tional Park contains two main branches, toric influence of humans is unknown, in separate watersheds: the South Fork but it is possible that a few special status (which flows from its headwaters at the species may have been introduced. Cur- southern tip of the Clark Range through rently, the greatest effect of human activity Wawona and exits the west boundary is found where flat topography, relatively of the park a few miles downstream of easy access to the riverbank, or structures Wawona at an elevation of 1,100 meters) occur. The concomitant increase in the and the main stem (which flows from number of people present leads to greater its headwaters between the Clark and disturbance of the environment. The im- Cathedral Ranges through Merced Lake pact on special status plant species is more to Yosemite Valley and exits the park to likely if a high-activity area coincides with the west at El Portal, at an elevation of an unusual habitat. This type of area was 600 meters). These two branches join therefore the focus of the surveys con- several miles west of Yosemite in the ducted for this report. Sierra National Forest. Within the park boundary, these two branches follow Effect of Invasive Species on similar trajectories: they have each cut Special Status Plants deep channels into the varied layers of ancient rock that once were sea floor, Non-native species have dramatically carbonate deposits, upwelling molten changed the composition of plant com- rock, or remnants from volcanic events munities in the western U.S. over the past or erosional deposits. From the headwa- few centuries. Many non-native species are ters of these branches, where the crest of strong competitors and have shown them- the Sierra Nevada reaches up over 4,000 selves to be able to successfully disperse meters, to the western park boundary, widely and compete with native species they pass through a variety of plant com- for habitat and have thus earned invasive munities, from alpine at the summits, to species status. Those native species with subalpine, montane and finally through restricted ranges and specialized habitat mixed hardwood and conifer that inter- requirements (such as most of Yosemite’s digitates with chaparral community types special status species) are especially vulner- that barely pass the western park bound- able to local extirpation where out-com- ary. Much of the river channel terrain is peted by invasive species. Yosemite’s early extremely rugged, bordered for most of protection, its lack of roads and the efforts its length only by pedestrian and pack of an active non-native prevention, detec- stock trails, with paved roads maintained tion and eradication program have all been only between El Portal and the upper end instrumental in slowing the spread of weed of Yosemite Valley on the main stem and species. Continued vigilance is necessary, for a few miles in the vicinity of Wawona however, as new non-natives are constantly on the South Fork. Both branches are entering the park. For example, an assess- largely unnavigable as they flow rapidly ment of herbarium records collected over and are punctuated at regular intervals the past 160 years reveals that non-native

3 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

species have appeared in Yosemite Valley Effect of Climate Warming and at an average rate of 1.7 per year (Dean Nitrogen Input Taylor, unpublished data). Although most of these non-natives have either remained All waterways of the park are showing in low numbers or have been eradicated, increases in the prevalence of certain some have proven to be highly invasive species of filamentous algae in the gen- locally and have become a serious threat to era Mougeotia and Spirogyra. These are native plant communities within the park. native species that grow more profusely The two that pose the most serious threat with increases in water temperature and to special status species in the Yosemite nitrogen availability (Colwell et al. 2010, Valley, Wawona and El Portal segments of unpublished report). These algae compete the Merced River are Himalayan black- with other aquatic plants for light and berry (Rubus discolor), and velvet grass space. The submerged aquatic special sta- A native species of filamentous (Holcus lanatus), both of which can attain tus species that have been located within algae in the genus Mougeotia high densities and large population sizes the study areas and thus would be most becomes dominant in lower on riverbanks, in moist forest openings impacted by this shift in species composi- park water bodies as channel and in bottomlands where most special tion, are common mare’s-tail (Hippuris flows drop and water warms. status species are located. The presence of vulgaris), western quillwort (Isoetes occi- Climate change in the form of higher temperatures and less these invasives and the significant presence dentalis), and lesser bladderwort (Utricu- moisture, will likely expand con- of Kentucky bluegrass (Poa pratensis var. laria minor). Common mare’s-tail and ditions that favor filamentous pratensis) in Yosemite Valley meadows is western quillwort have been documented algae. documented in a related study (Ballenger in 2 meter deep water in a low gradient et al. 2011, unpublished report). Both stretch just above Nevada Falls, and likely Himalayan blackberry and velvet grass are exist in other deep, slow water stretches under aggressive treatment by the Yosemite in the upper reaches of the river, such as Invasive Plant Program, which is of long in Washburn and Merced Lakes. Lesser term benefit to special status species in the bladderwort was found in a pool in a Yo- affected areas. Kentucky bluegrass is not semite Valley meadow and at Lost Lake. It being treated in Yosemite. may occur at other sites as well.

4 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Methods

Methods The methods employed for this project stable habitats, so locations and habitats of were of two kinds: 1) an assessment of the known special status species would inform state of knowledge of the flora, and 2) con- where to focus current surveys. duct of new surveys in areas where current information was found to be lacking. Historical Records Reviewed

Assessment of Prior Knowledge Historical observations of plant species were tracked down from a variety of The flora of the Merced River is incom- sources. Anecdotal accounts from the latter pletely known. Although easily accessible nineteenth century (Brewer 1864; Muir areas (near roads) have been well inven- 1869; Olmsted 1865) offer useful general toried, the many sheer rock walls have descriptions of the habitats encountered put large areas out of reach of nearly all by the authors. More detailed descriptions botanists. The areas more than one day’s from targeted botanical and floristic studies hike from a trail head have also been very for the Yosemite region began appearing in sparsely studied. This means the South early twentieth century (Brandegee 1903, Fork corridor upstream of Wawona and the Hall 1911). Ecological studies were con- main stem corridor upstream of Washburn ducted each summer from 1925 to 1943 in Lake are essentially undocumented botani- Yosemite by the students of the Yosemite cally. A list of park special status plants that Field School and the unpublished class re- have been documented to occur within 0.5 ports are available in the Yosemite Library. kilometer of the Merced River (main stem A definitive flora of Yosemite was published Below, Willis Lynn Jepson’s or South Fork) prior to 2010 surveys was by Steve Botti in 2000, describing 1473 herbarium specimen of the developed so that surveyors would have a vascular plant taxa. (All varieties and sub- Mono Hot Springs primrose sense of what their target species and target species are included in the total.) In 2010, a (Camissonia sierrae ssp. alticola) habitats would be (Appendix 4). Future technical flora of the Yosemite region was collected at Merced Lake in surveys will doubtless add to this list. released by Dean Taylor, which includes 1927. Efforts to locate this plant Typically special status species are found 1671 taxa within the park boundaries. at Merced Lake in 2010 failed, but a site in Little Yosemite Val- grouped together in unusual or in highly ley reported by Steve Botti was found. Lower left, Thousands of these tiny plants (inset), as well as a dozen other tiny annual species, surround the data taker in this vernally moist forest opening containing shallow gravel over bedrock.

5 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

Left, California bog asphodel (Narthecium californicum), is a showy special status species that in our region is found on rock ledges in the spray zones of waterfalls and in a single fen meadow. Right, a fifth location of this species, and the first for Yosemite Valley, was noted in 2009 on the wall to the right of Bridalveil Falls, where it dominates ledges in the spray zone. This new dis- covery illustrates how poorly known is the flora of the walls of Yosemite Valley.

The definitive source of information for status species with herbarium specimen species occurrences is the herbarium vouchers. specimen. This simple procedure of collecting diagnostic plant parts (flow- Historic Collections not Relocated ers, fruits, leaves, etc), pressing them flat, drying them and mounting them on An effort to relocate all species previously an archival sheet of paper with a label documented from Yosemite Valley was containing pertinent location and mor- begun by Dr. Dean Taylor in 2009. Dr. phological information has been standard Taylor has compiled a spreadsheet with all practice for several hundred years. It herbarium specimen records labeled “Yo- remains the accepted method of refer- semite Valley” (available from the authors encing species for presence in a location upon request), amounting to just over 900 and for verification of their identity. For species. He has attempted to relocate all of this reason, we used herbarium specimen these documented species within Yosem- database records as our primary source ite Valley and has so far located approxi- for past presence/absence data, referring mately 500 of them. A factor complicating to descriptive records to augment the this endeavor is that collections made in data or replace it in the few cases where the period between 1864 and 1890 typi- the original herbarium specimen record cally listed for location only “Yosemite” or is missing. Appendix 3 contains a table of “Yosemite Valley”, meaning the area of the 51 special status species expected to oc- Yosemite Grant, which included Yosemite cur in the Merced River corridor within Valley, its slopes, and the adjoining up- 0.5 km of the river channel. These species lands one mile back in all directions from have herbarium records that either state the valley rim. For this reason, many of the plant was found within this area or, the 900 species documented from this era for older specimens, have records that actually reside on the walls of the valley imply that they were found within this or even beyond the rim, making reloca- area (See discussion in next section.). tion and assessment of presence/absence an enormous and difficult task. Much This study also contributed to the in- additional terrain remains to be covered formation archive of specimen data by by this effort so at this point in time none documenting new occurrences of special of the 400 missing species can be defini-

6 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Methods

tively stated to have been extirpated from California Academy of Sciences. No Yosemite Valley. The surveys conducted species of Erythronium has since been for this project were structured so as to found in Yosemite. Tooloolaweack contribute to the data collection for this Canon is now known as Illilouette ongoing effort. Canyon, and the upper iron bridge is likely in the vicinity of Happy Isles The following species on the special (Linda Eade, pers. comm.), although status plant list (Appendix 3) have not there is also an iron bridge above Il- been previously targeted for surveys in lilouette Falls on the Panorama Trail. the five areas covered by this project, Four species of Erythronium, all rare, and were not observed in 2010 surveys. occur in small populations outside of However, we consider these species either the Yosemite park boundaries. Pos- overlooked by this survey or not occur- sibly the Illilouette population was ring within the primary survey area for extirpated in Yosemite by overzealous this project: spurred snapdragon (Antir- early collecting, but it is entirely pos- rhinum leptaleum/Sairocarpus cornutus), sible that it still exists on rarely-visited Sierra sun cups (Camissonia sierrae ssp. rock faces or moist, shady wooded sierra), canyon sedge (Carex fissuricola), slopes. silver sedge (Carex canescens), Northern mannagrass (Glyceria borealis), redray 2) A specimen of the pansy monkey- alpinegold (Hulsea heterochroma), false flower Mimulus( pulchellus), collected pimpernel (Lindernia dubia var. annagal- in 1900 by the monkeyflower specialist lidea), azure penstemon (Penstemon azur- F.T. Bioletti, is labeled “Yosemite Val- eus ssp. angustissimus), Purdy’s penstemon ley”. This is a typically vague location (Penstemon heterophytus var. purdyi), lacy of Bioletti’s and could indicate the scorpion-weed (Phacelia tanacetifolia), slopes of the valley, possibly even Big Nuttall’s pondweed (Potamogeton epihy- Meadow (a current location of this drus ssp. nuttallii) box saxifrage (Saxifraga species); the label should be consid- oregana) and Sierra skullcap (Scutellaria ered inconclusive evidence of this bolanderi ssp. bolanderi). These species species having existed here in the past. require further survey effort. This species prefers vernally moist, sparsely vegetated granite pans, of There are, however, five species histori- which there are many on the slopes cally documented from Yosemite Valley around Yosemite Valley that remain but which recent targeted survey efforts unexplored. and the 2010 surveys have not turned up, raising the possibility that these have been 3) The Western yew is known from extirpated from Yosemite Valley: two collections (John Muir, 1874, in “Yosemite Valley” and J.W. Congdon, 1) The fawnlily, also known as the dog- 1901, in “Yosemite”) and the follow- tooth violet, presents the most inter- ing mention by Katherine Brandegee esting ‘missing plants’ case. Katherine (1891): “The yew (Taxus brevifolia) Brandegee (1903) states “The purple grows near the water in the cañon dog-tooth violet (Erythronium pur- of the Merced. The “nutmeg-tree” purascens) is found on the south side (Torreya californica) grows also in the of the valley, from the upper iron cañon of the Merced but farther from bridge to Tooloolaweack Canon.” the water. Neither this tree nor the last There is no specimen of this spe- quite reaches the valley.” These pieces cies from Yosemite known, although of information suggest that this tree it would have been normal practice at one time inhabited the stretch of for Katherine to have made a speci- river between Arch Rock and Yosem- men, perhaps it was lost in the 1904 ite Valley. It has not been collected or earthquake and fire that destroyed the reported since 1901 and we have not

7 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

located any during the course of this was described from a single collec- survey. It is thus possibly extirpated tion in Yosemite Valley made by Willis from this drainage, signifying a range Lynn Jepson in 1900 but has not been retreat to the north. The nearest extant relocated. The label for this specimen location to the north is in Basin Creek lacks further detail, but the host plant in the Stanislaus N.F. No specimens shown on the sheet is mustang mint are known to the south. (Mondarella lanceolata), a dry ground annual, which reduces the potential 4) Sierra sweetbay (Myrica hartwegii) may habitat area somewhat. This species have occurred in the section of river has not been recognized by current between Yosemite Valley and El Portal. dodder specialists, the distinguishing A systematic survey for California feature (the length of the anther fila- sweet bay Myrica hartwegii along the ments) being considered to be insuf- main stem of the Merced River from ficient to distinguish it as a variety. This Pohono Bridge at the lower end of Yo- subspecies will not be recognized as semite Valley west to the park bound- distinct in the forthcoming edition of ary was conducted and no specimens the Jepson Manual (Baldwin 2012). of this species were observed. There are only two records of this species Survey Methods occurring in the main stem, Katherine Brandegee’s statement that “Myrica The Merced River flows a total of 81 miles hartwegi, a rather rare wax-myrtle, within the park boundaries, most of which though not found in the valley grows is difficult to access. To survey the entire on the Merced below it” (Brandegee corridor was beyond the time or funding 1891), and an entry in Hall’s Flora available to gather data for this report, of Yosemite which states, “Rare, but so targeted surveys based on the experi- found on Big Creek, below the Mari- ence of botanists Dr. Dean Taylor and posa Grove, and in the Merced Canon Dr. Alison Colwell were undertaken. The below the Yosemite.” (Hall 1912). No focus of the 2010 surveys was primarily on historic herbarium specimens of this heavily used areas and within those areas plant in the main stem of the Merced the focus was on potential special status River are known to exist, so this spe- species habitat. cies was probably never common in this drainage. The vague descriptions The following survey methods were used: quoted above leave open to interpretation whether the species ever existed 1) Habitat-targeted survey and species below the valley within the current list. When surveys were conducted by park boundary or further down the botanists experienced with the flora, Merced River Canyon. A logical place the targeted area was walked through to search would be at or downstream in such a manner as all likely habitat of the junction of the South Fork with for special status species was surveyed. the main stem, as this species could Methods used to determine likely hab- easily have dispersed down the South itat were aerial imagery, topographic Fork from the populations in Wawona maps, and visual inspection from mul- area. If Sierra sweetbay cannot be tiple vantage points. The surveyor kept confirmed on the main stem below the a list of species observed and species confluence with the South Fork, then not previously documented in the area it should be presumed extirpated from were collected for vouchers. Any spe- this section of river. cial status species populations encountered were mapped, photographed 5) A variety of the parasitic plant spe- and databased. In this manner about cies known as California dodder 25% of the total target area would be (Cuscuta californica ssp. apodanthera) covered visually but a higher percent-

8 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Methods

age (50%–75%) of likely special status ness to the headwaters were not surveyed plant habitat would be covered. for this report. Similarly, the main fork of the Merced River was surveyed from 2) Gridded survey. When surveys were 2 km upstream of Merced Lake through conducted by crews of inexperienced Yosemite Valley to the west park boundary botanists, the crews were trained by at El Portal. The portion of the river from experienced botanists on what species above Merced Lake to the headwaters was of special status plants would occur in not surveyed for this report. Appendix 3 the area, either by showing the crew lists the special status species with exist- examples of the species and habitat ing documentation within 0.5 kilometer of beforehand, or giving them photo- the river channel, from the park bound- graphs and key characteristics to look ary to the Merced River headwaters. The out for. Crews walked the target area upper reaches of both rivers not covered in parallel, approximately 15 meters in this survey are otherwise very sparsely distant, covering 75-90% of the target documented, and we predict that many area visually. If a crew member en- more populations of special status species countered an unfamiliar plant, a por- will be found in these segments. However, tion of it was turned over to an experi- in areas of low human usage, we do not enced botanist for identification. expect to find significant adverse impacts to existing populations of special status 3) Species-targeted survey. At sites where species. This was the case for the special special status species had been ob- status plant survey conducted for the served historically (from reported Tuolumne Wild and Scenic River planning observations such as in Botti, 2000, in 2006. For that survey, the entire length or from historical specimen records of the Tuolumne River and Lyell and (Consortium California Herbaria, Dana Forks was surveyed to 0.5 kilometer 2011), targeted surveys were under- each side of the river channel (Acree et al. taken. In this case, either experienced 2007). Special status species were found botanists or experienced botanists scattered along the entire length of the with additional crew members sur- river, but primarily in areas with unusual veyed the area completely. In all cases, habitats (waterfall spray zones, mineral an experienced botanist was within springs, areas with unusual geology). Ad- hailing or radio contact distance and verse effects were found to occur primar- if a crew member came across an unfa- ily in high-visitation areas. Therefore, the miliar plant, the experienced botanist scope of this project was reduced to focus was called in to identify it. effort on those areas along the Merced River with the greatest human use: Mer- In all types of surveys, both natural and ced Lake, Little Yosemite Valley, Yosemite human-affected vegetation was surveyed, Valley, Wawona and El Portal. including landscaping on park lands occupied by hotels, visitor services and GPS Data Collection and Analysis residents. Specimens collected were dried, pressed and processed according to ac- GPS data were collected with Trimble cepted herbarium standards. Juno SB units. For all rare plant populations, at least 50 points were collected and Areas Not Surveyed for This Study averaged for point position data. A data dictionary with plant name, observer and For this survey, the river channel and data on the population such as number, banks of the South Fork of the Merced phenology and population diameter were River were surveyed from the wilderness recorded. Population perimeters were also boundary above Wawona to near the park collected for large populations using ei- boundary downstream of Wawona. The ther a line or polygon shapefile. Points and upper reaches of the river within wilder- lines were buffered based on population

9 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

diameters to create polygons. Lines and Location of Data and Specimens polygons were also converted to points. Both points and polygons are displayed on The mapping data, collected during this the maps. Projection is NAD 1983 11N. survey and containing actual occurrence The data were not geo-corrected and was perimeters, will be posted in 2011 on checked visually in ArcGIS for accuracy. the park GIS data server for Yosemite staff and will be available from Yosemite Map Information Resources Management and Science to authorized users upon request. The cita- The maps generated by the 2010 surveys tion for this report will be posted in the are intercalated into the relevant sections Yosemite Digital Science Library Catalog, of the report. Where possible, the same with the full text version of this report color was used on every map for the special available to Yosemite staff, and upon re- status species that occur on more than one quest by authorized users, on the Yosemite map. Maps display GPS data collected in Sharepoint site. 2010 for this study as well as GPS data collected in 2003-2007 for previous studies, if Specimen label data will be retained in the older data is in or near the area of inter- the Yosemite Museum Herbarium (YM) est for this study. Most special status spe- specimen database. Special status species cies occur in patches too small to display data will be compiled and submitted to on maps of this scale. Therefore, the point the California Natural Diversity Database or polygon data that represent their occur- (CNDDB) of the California Department rences was converted to square points of a of Fish and Game in 2011. standard size for display on the maps in this report. Those with occurrences larger than Specimens of plants collected as part of the standard display size were left in their this study will be deposited in 2011 at the actual polygon shape. following herbaria, according to the requirements stated in the Research Collect- A few special status species have names ing Permit YOSE-2010-SCI-0087: too long to fit on the map legends so they were truncated as follows: Arabis • All unicate specimens of all taxa col- repanda var. repanda is shortened to lected reside at Yosemite Museum Arabis repanda, Camissonia sierrae ssp. (YM); alticola is shortened to Camissonia sierrae, Lithocarpus densiflorus ssp. densiflorus • Duplicates of vascular plants, lichen- is shortened to Lithocarpus densiflorus, ized and non-lichenized fungi reside Madia elegans ssp. vernalis, is shortened to at University of California Herbarium, Madia elegans, and Plagiobothrys torreyi Berkeley (UC); var. torreyi is shortened to Plagiobothrys torreyi. Rare species which have been • Duplicates of mosses and liverworts found since the park special status list was reside at California Academy of Sci- last updated are mapped and listed in the ences, San Francisco (CAS); map legend under the heading “Candidate Species”. These species will be considered • Duplicates of freshwater algae reside for special status when the park special at New York Botanical Garden, Bronx, status species list is next revised. New York (NY).

10 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Results & Discussion

Results & Discussion The following results and discussion sec- segment has its own character and its own tions have been combined under head- special status plant issues. The survey ings for each river segment, as each river maps are located at the end of the report.

At the upper end of Lake Merced eight miles east of the Nevada Fall is a beautiful grove of [aspen] which are 60 to 80 feet high with trunks 1 to nearly 2 feet in diameter at 4 ½ feet.

Single individuals [of white fir] of exceptional size are often found on gentle mountain slopes or in canon bottoms in deep soil. Near the upper end of Lake Merced (east of Yosemite) is a tree 160 feet high with trunk 8 ½ feet in diameter at 4 ½ feet above the ground…These individuals of exceptional size which arrest the attention of the traveler are in most cases apparently of great age.

– Willis Lynn Jepson, 1909.

From: The Trees of California.

Merced Lake less been a preferred stopping place for travelers for millennia. In the last century, Results of Surveys of Merced Lake the infrastructure to support travelers’ needs has been made semi-permanent: Drs. Colwell and Taylor surveyed the vi- a High Sierra Camp has a barn, a dining cinity of Merced Lake on July 13-15, 2010, hall and a fleet of small cabins. A kilome- paying particular attention to site where ter uphill is the site of the Merced Lake previously reported special status plants Ranger Station, occupied by a ranger all occurred (Appendix 3) and to invasives summer and a revolving suite of park staff around developed areas. A candidate spe- on various projects. Little has changed in cial status species, Nevada City buckwheat the way of life here in a hundred years: (Eriogonum prattenianum) was surveyed hikers come and go, and pack strings stop for the first time. This species was found at to deliver supplies here or pass through to Merced Lake but is discussed in the Little supply trail crew camps farther in the back Yosemite Valley & Vernal Falls section, as country. Horses and mules wait patiently it was also found from Bunnell Point to for their loads in corrals, or wander in above Merced Lake. certain meadows in search of forage. This place functions as a transit depot, serving Discussion of Special Status Species park functions in the entire upper Merced Occurrences River watershed, as it has for a century. As is the case with any nexus of human activ- The upper main fork of the Merced River ity, the typical threats to vegetation are flows into many granite basins on its way found here: overuse of unusual habitats downhill, and two of these basins are that harbor unusual species and introduc- large enough that sizable, deep lakes have tion of alien species. formed: Washburn Lake and Merced Lake. In a region where glaciers have rela- Notable Trees tively recently scoured away soils to the substrate rock, Merced Lake has already The unusually deep soils here have developed considerable soil, especially fostered the growth of some notable tree at its upper end. This hospitable oasis, at specimens. When W.L. Jepson visited 2200 meters elevation and one hard day’s Merced Lake in 1909 as part of a 150-per- hike from the nearest road, has doubt- son Sierra Club outing, he remarked on

11 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

Right. remains of a stand of aspen at Merced Lake back- packer’s camp noted by W.L. Jepson on a Sierra Club trip in 1909. Above, a champion white fir, likely noted by Jepson on that same visit, still stands beside the trail west of the High Sierra Camp. A stone stairway has been constructed across its base to avoid damage by the heavy stock use this trail sees. This strategy appears to be working as intended but the optimal a “beautiful” stand of aspen there. Cur- degraded riparian site noted was a sandy situation for this and the other rently there is a healthy stand of small- area of about 50 meters in length between enormous white firs next to the diameter aspen along the trail a kilome- the old barn and the river, where the trail in the vicinity would be to ter west of the High Sierra Camp and a campers apparently congregate to swim. reroute the trail farther from senescing stand of very large aspen in and this grove of trees. around the Backpackers Camp, which we The employees of the Merced High assume is the stand Jepson referred to in Sierra Camp have demarcated walkways the above quote. Most of the trunks in this within the camp with stones and native stand have fallen over and the rest look vegetation (notably: pinewoods horkelia diseased. Aspen are relatively short-lived (Horkelia fusca), prettyface (Tritelea ixioi- trees and their stands naturally go through des), Western needlegrass (Achnatherum cycles of growth and senescence, but it occidentale) and silver bird’s-foot trefoil should be noted that surface hydrology (Lotus argophyllus) is regenerating in the changes (e.g., drying out of the soil) possi- intervening spaces very nicely from what bly induced by the devegetation caused by the staff referred to as a ‘dustbowl’ in the campground may have had an impact previous decades. In the paths themselves, on this stand of trees. in the spring, grows Plagiobothrys torreyi var. diffusus, an ephemeral annual native Impacts of Human Activity plant that colonizes disturbed sandy areas (a flood-follower). A few non-native spe- The High Sierra Camp at Merced Lake cies such as hairy rupturewort (Herniaria has surprisingly few impacts on vegetation hirsuta), purple sandspurry (Spergularia outside of its immediate perimeter. The rubra) and Kentucky bluegrass (Poa pra- caveat for this statement is that at the time tensis), occur in the paths and behind the of our visit, Merced Lake was in flood, so cabins. The density of Kentucky bluegrass we could not observe shoreline impacts behind the tent cabins suggests that it may closely, but they appeared to be limited to have been planted there at one time to a shore perimeter trail. The only severely create a lawn. These non-natives don’t ap-

12 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Results & Discussion

Left, paths demarcated by Merced Lake High Sierra Camp staff turned a long-standing dustbowl into a native plant regeneration zone. Right, the density of non-native Kentucky bluegrass behind the tent cabins suggests that grass-seeding may have been practiced at some time in the past.

pear to be colonizing beyond the human the potential to the adversely impact sur- use area. rounding plant communities if they do.

The DNC horse corral is in a wooded The pack stock were fed processed grain conifer area with thick duff and few un- at the corral before being turned out to derstory herbs and has no invasive species forage. The spilled grain is an attractive around it. The DNC stock are no longer nuisance for wildlife as birds, rodents and allowed to graze the fen & wet meadow deer are clearly accustomed to coming across the trail to the south of the corral into the corral to scavenge it and were and this meadow now supports a nice there nightly during our survey. Rodents diversity of typical native species, although were occupying the grain storage shed in no rare species were found there (possibly the Merced Lake Ranger Cabin. the lack of special status species in this meadow is a lingering result of past graz- The nearby meadow that the stock are ing or perhaps it is natural). allowed to graze in was not observed to have the above-mentioned species of The NPS horse corral contained several weeds, but was inundated at the time of non-native species that had not previously visitation and should therefore be rein- been documented from this area: shep- spected for non-natives at a later calen- herd’s purse (Capsella bursa-pastoris), dar date (in August or September). The Jerusalem oak (Dysphania (Chenopodium) grazing meadow could not be assessed botrys), orchard grass (Dactylis glomerata), for special status species at the time of cheeseweed (Malva pauciflora), pineapple visit because it was inundated. The MRP weed (Matricaria matricarioides), annual Meadow Report discusses the condition bluegrass (Poa annua), Kentucky blue- of this meadow in September 2010 – no grass (Poa pratensis) and burning nettle special status species were observed there (Urtica urens). These finds represent sig- on that date (Ballenger 2011). nificant range and elevation extensions for these species, which are otherwise typically found in locations below 4,000 feet. These species could have been introduced The NPS horse corral impacts on the hooves or gear of the pack animals only a small area. However, sev- from locations where they are already eral new species of non-natives established such as the Yosemite Valley were documented from this site. Stables area, or they could have arrived in None appear to be moving away the intestines of the animals if the animals from the corral but vigilance is important, as this is a potential had consumed these species at lower point source of non-native spe- elevations. These species do not appear cies which could have a large to be colonizing locations away from the impact if they colonize the sur- corral at the current time, but they have rounding area.

13 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

Left, the large, sunny, vernally moist gravel site between the barn and the dining hall in Merced Lake High Sierra Camp was the best potential habitat of Mono Hot Springs evening primrose in the area. That species was not found here, possibly due to historically high human impact at the site. However, the native species, Torrey’s popcornflower (at right), colonizes similar habitats and was found here in abundance.

It was the intention of the survey crew failure of this survey to find this species, it to conduct surveys in Merced Lake for cannot yet be said to be extirpated as there aquatic special status species, but the is much potential habitat surrounding the unusually high water proved too cold for lake for this tiny plant that was not sur- more than a brief look in one spot, even veyed. However, the best potential habitat with wet suits. Western quillwort (Isoetes observed was in the campus of the Merced occidentalis) very likely occurs in Merced High Sierra Camp, so it is possible this Lake but should be surveyed for when species did occur there prior to permanent water levels are at their lowest and water human habitation and was extirpated by temperature is at its highest. trampling. This species was also sought in appropriate habitat in Echo Valley and The rare plant Mono Hot Springs evening along the “high water trail” from Little Yo- primrose (Camissonia sierrae ssp. alticola) semite Valley (the route Jepson would have was sought by this survey, but not found, used to travel to Merced Lake in 1909) but at Merced Lake. A 1909 collection by W.L. was not found. This plant should be sought Jepson lacked specific details on location, again in the Merced Lake area in future stating only “Merced Lake”, so despite the years in mid-June to early July.

14 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Results & Discussion

There are falls of water elsewhere finer, there are more stupendous rocks, more beetling cliffs, there are deeper and more awful chasms, there may be as beautiful streams, as lovely meadows, there are larger trees. It is in no scene or scenes the charm consists, but in the miles of scenery where cliffs of awful height and rocks of vast magnitude and of varied and exquisite coloring, are banked and fringed and draped and shadowed by the tender foliage of noble and lovely trees and bushes, reflected from the most placid pools, and associated with the most tranquil meadows, the most playful streams, and every variety of soft and peaceful pastoral beauty.”

– Frederick Law Olmsted, 1865.

Little Yosemite Valley & Vernal and greater opportunity for invasive spe- Falls cies to be transported here. The Mist Trail, Yosemite’s most popular hike, is built right Special status species wood Results of Survey from Merced Lake to through such habitats, which is exactly saxifrage (Saxifraga mertensiana) Happy Isles what makes this trail both attractive to (top) and Sierra false coolwort visitors and a tricky place to manage for (Bolandra californica) (bottom) Drs. Colwell and Taylor walked this sec- special status species. were observed along the trail in tion of the Merced River on July 12 and on the spray zone. 16, 2010. This route, also largely a high hu- The most problematic site on the Mist man impact area, was surveyed for expect- Trail is the spray zone of Vernal Falls. The ed special status plants (Appendix 3) and area is heavily infested with non-native a species list of all plants observed was invasive species. Velvet grass (Holcus created. Special status plants encountered lanatus) and Kentucky bluegrass (Poa pra- were mapped and data collected accord- tensis) constitute a significant amount of ing to standard methods for special status the vegetation cover, crowding out native species. Where special status plants had species. Bristly dogtail grass (Cynosurus been reported by earlier studies, but not echinatus) is also established there and yet mapped, targeted surveys were done. will likely continue to increase. The ability The locations of special status species in of non-native invasives to invade this site this section are shown on portions of two is excacerbated by visitor trampling off maps: Little Yosemite Valley Map and on trail onto moist ground and vegetation, the left half of Merced Lake Vicinity Map. creating spots of bare ground for new arrivals to establish in. This spot would Discussion of Special Status Species be a difficult place to treat invasives, but Occurrences treatment should be considered because: a) Waterfall spray zones are a rare habitat Special status species in this section were and home to uncommon species, and b) associated with humid or wet environ- Vernal Falls is a prominent natural feature ments of three types: that is degraded by unrestricted foot- traffic and deserves to look its best to the 1) Spray zone of waterfalls many eyes that see it.

2) Seepage areas Educational signage about the plants of this specialized habitat and better physical 3) Slow-flow, deep-water section of river barriers to leaving the trail in this section may curtail off-trail damage caused by These habitats are small in size, so the photographers seeking a different angle plants specialized for them tend to have or hikers looking for a place to take a small populations. These same areas are bathroom break. This location is a high- attractive to wildlife and humans so suffer visibility, high-visitation showcase of one a relatively greater burden of trampling, of Yosemite’s wonders and therefore the

15 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

Invasive velvet grass is now a dominant species in the spray zone at Vernal Falls. In addition, social trails destroy vegetation in this rare habitat and open up ground for colonization by more non-native species.

Below right, a granite slope with condition of the vegetation at this site Detmer (a wetland specialist) in 1929 at water sheeting across it, with should be addressed. the base of Nevada Falls, and this is the the Merced River above Little only specimen ever collected in Yosemite. Yosemite Valley in the back- In contrast, as the Mist Trail passes We inspected the area around the base ground. The specialized plant community on the rock in the Nevada Falls, it skirts around the spray of the falls and found none of the ‘bog’ foreground is the usual habitat zone. Invasive species and trampling are habitat that Freda described on her label. of the special status species not nearly as serious a problem here as It is possible that either past hydrologic Yosemite tarweed, three-way they are at Vernal Falls. A specimen of alterations done to Nevada Falls or a sedge and cut-leaf monkeyflow- Kobresia bellardii was collected by Freda rockfall removed a bog site, or that Freda er. These species also occasionally form small colonies on Yosemite Valley floor, the seeds likely having been swept into the valley during floods. Below left, three-way sedge grows in a vernally inundated section of path behind the Ranger Club, marked by pink flagging.

16 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Results & Discussion

was referring to Lost Lake at the base of Many trailside seepages be- Half Dome. tween Little Yosemite Valley and Merced Lake contain the diminutive annual Yosemite tar- Seepage areas on rock slabs, rock faces, weed (Jensia yosemitensis). The across gravel slopes occurred regularly moist soil at a few of these sites from the base of the Mist Trail to Mer- is disturbed by deep hoofprints ced Lake. Most were in good condition, left by horses going to water. even when adjacent to the trail (due to smart trail construction) but a few showed damage from pack stock leaving the trail in search of water. Seepage sites typically contained the following special status species: Bolander’s tarweed (Jensia bolanderi), 0.25 km distance, is a population of Sierra Yosemite woolly sunflower Eriophyl( - sun cups (Camissonia sierrae ssp. alticola). lum nubigenum), cut-leaf monkeyflower This population, last observed by Steve (Mimulus laciniatus), Bolander’s saxifrage Botti in the 1980s, was found and mapped. (Bolandra californica). However, the di- It is on a flat, vernally moist, granite gruss minuitive densetuft hairsedge (Bulbostylis opening near a trail to Half Dome. The capillaris) which is found in such habitats site appears undisturbed, although several in so many places in the Tuolumne River festoons of fresh orange flagging tape Canyon, was not observed, despite being were tied on trees adjacent to the site, targeted in these sites. apparently to mark a cross-country route. The flagging was removed because it was Trampling Impacts unmarked. An increase in off-trail traffic through this open site (for instance, if In Little Yosemite Valley the riverbank is there is a popular climb behind this site) degraded where the trail meets a flat sec- could easily impact this rare plant, as its tion of river as hikers like to access the wa- patch size is only five meters in diameter. ter here to cool off. In this section is where a submerged aquatic special status species The unusual quaking bog at Lost Lake, observed in the Merced River, Western which contains the special status plant quillwort (Isoetes occidentalis), was found, species bugleweed (Lycopus uniflorus) and as was an emergent aquatic special status lesser bladderwort (Utricularia minor) as species, common mare’s-tail (Hippuris well as many other unusual species, re- vulgaris). This species had been observed mains little visited and consequently is in in the slow-moving section of the river good condition (a well-worn social trail to beside Little Yosemite Valley Ranger climbing routes bypasses closely this lake), Station during aquatic habitat surveys in but this fragile habitat should be moni- 2008. More extensive surveys for this spe- tored for an increase in off-trail use. cies were not undertaken in 2010 due to fast-flowing, cold water. This species may At the east end of Echo Valley, about one occur in other spots of the river between kilometer west of Merced Lake is a small, Little Yosemite Valley and the headwaters ephemeral mineral spring located three wherever there is still water 2 meters or meters below the trail. Mineral springs in more in depth. Yosemite are an unusual habitat that frequently harbor species of plants specialized The camp and ranger station in Little for highly mineralized wet soils, some of Yosemite Valley are in an appropriately which are special status species. This par- dry site somewhat distant from the river ticular spring is undisturbed by trail traffic where they are not in the immediate vicin- but does not harbor special status species. ity of special status plant populations. The nearest special status plant population to A mineral spring also occurs in the trail the campground and ranger station, at itself between Merced and Washburn

17 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

Lakes, 2 kilometers west of the Merced in this river section. This is a candidate Lake Ranger Station (This location is not for special status, as one of two previously displayed on the Merced Lake Map as documented occurrences in the park was it occurs to the east of the map extent. in the vicinity of Merced Lake (the other The GPS coordinates are: UTM Zone is on the South Fork of the Merced River 11/289896/4178076 NAD83) (Moore et upstream of Wawona). Our surveys con- al. 2007). This spring arises on the north firmed that this species is widespread from side of a switchback and flows into the Bunnell Point to above Merced Lake, with trail. The trail at this spot should be routed scattered populations on rocky canyon away from this mineral spring. The reasons slopes on the north side of the Merced are: a) mineral springs are heavily used by River down to the water’s edge (but, wildlife seeking salt, b) special status plant oddly, it was not observed on the south species typical of mineral springs may have slope). The Merced Lake map indicates existed here prior to the trail’s construc- several populations but not all that occur tion, and c) the mineral spring makes the here. The population found near the High trail muddy, contributing to erosion. Sierra Camp appears to be stable, and it has even colonized the stonework of the In Echo Valley the trail goes through wet trail near Merced Lake. This species is not bottomland and is in need of either rein- threatened by human activity in the area forcing work to bring it above the water as it prefers rock ledges and cracks in rock table or a reroute around the wet area. faces and there is much secure habitat of These sections of trail are muddy and have this sort in the area. This species will re- multiple paths. The problem is exacerbated main on the candidate list pending further At left, a mineral spring at the by the high volume of pack stock traffic taxonomic study to determine the limits of upper end of Echo Valley is through Echo Valley. No special status spe- its range in the central Sierra Nevada. located only a few meters below cies were observed in this section in 2010. the trail (the vantage point from which the photo was taken), but Special Status Species since its flow is away from the Candidate Special Status Species trail, the plant habitat, which The population of redray alpinegold (Hul- is highly restricted to the salt Nevada City buckwheat (Eriogonum prat- sea heterochroma) at Twin Bridges record- water perimeter, is unaffected tenianum var. prattenianum) was surveyed ed (but not vouchered) by Steven Botti by the trail traffic, although it is riddled with wildlife tracks. At right, a mineral spring west of Washburn Lake flows into and is diverted by the trail (creating reddish mud) and the result is loss of use to mineral spring specialist plants and wildlife and poor trail quality.

18 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Results & Discussion

Above, Nevada City buckwheat, which prefers granite crevices, colonizes stonework in trail near Merced Lake. Left, Nevada City buckwheat thrives in a granite crack next to power cable at Merced Lake High Sierra Camp.

(2000) was not found. Instead, a large we suspect that there was a past name population of Yosemite tarweed (Jensia error in the rare plant records. A species yosemitana) was found in approximately of tarweed (Madia sp.) that could not be the same perimeter as the mapped redray identified in the field was also mapped on alpinegold. Twin Bridges is not typical the north slope above twin bridges, within habitat for redray alpinegold, which is the perimeter of the Yosemite tarweed. a foothill chaparral species, but this is This species is on loan to an expert for typical habitat for Yosemite tarweed, so identification.

19 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

Yosemite was all one glorious flower garden before plows and scythes and trampling, biting horses came to make its wide open spaces look like farmers’ pasture fields. Nevertheless, countless flowers still bloom every year in glorious profusion on the grand talus slopes, wall benches and tablets, and in all the fine, cool side-canyons up to the rim of the Valley, and beyond, higher and higher, to the summits of the peaks. Even on the open floor and in easily-reached side-nooks many common flowering plants have survived and still make a brave show in the spring and early summer.

- John Muir, 1912.

From: The Yosemite.

Yosemite Valley Note: Torrey’s popcornflower Pla( - giobothrys torreyi var. torreyi) is shown on Results of Yosemite Valley Surveys the Yosemite Valley- East Portion map in Ahwahnee Meadow, in the vicinity of the The floor of Yosemite Valley had been sur- site of the original collection from which veyed for rare plants using GPS technol- this subspecies was described. This variety ogy when this study was started. To survey of Torrey’s popcornflower has since been the entire valley floor was beyond the found to be widespread in Yosemite Valley scope of this project, so survey emphasis and its taxonomic relationship to the more was placed on the river banks, meadows widespread Plagiobothrys torreyi var. dif- and developed areas. Targeted surveys fusus is currently under review, so we did were done by Drs. Colwell and Taylor not include additional populations on the and by Park Botanist Lisa Acree over the Yosemite Valley or Little Yosemite Valley course of the season. Gridded surveys in maps in order to preserve clarity. a few areas known to harbor special status species were done by Dr. Colwell and field Discussion assistants. In addition, the Merced River Plan Meadow survey project crew alerted The natural role of the Merced River in this project staff when they found special Yosemite Valley is as an agent of cleans- status species in their plots and these data ing and renewal. Regular floods clear out were incorporated into these maps. duff, debris, and understory vegetation. This provides clearings for sun-loving The two maps titled: Yosemite Valley – species to thrive. It also exposes mineral East Portion and Yosemite Valley – West soil for seeds to germinate and establish Portion display the results of these sur- new populations without competition for veys. No special status species (excep- light from above. Nutrients are redistrib- tions were landscaping subjects discussed uted by the force of the floodwater and are below), were found in campgrounds, introduced by the settling of suspended housing areas or other intensively de- solids as the floodwaters slow and spread veloped areas. Nearly all special status across the floodplain. Seeds of species species were found in ares with at least from higher elevations are washed down brief inundation: meadows, oxbow cutoffs and planted with the sediment settling. or some other feature remaining from old Therefore, patches of species uncharacter- river channels or flood events. Nearly all istic of this elevation, both common and major wetland areas had at least one spe- rare, establish themselves in the moist soils cial status species occupant, but usually and flooded swales left by the flooding, not the same one. Occurrence of special at least for the short term. It is expected status species was widely distributed and that some of these will appear and disap- was highly patchy. Possible reasons for this pear with the normal river processes. The pattern are discussed below. following species marked on the Yosem-

20 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Results & Discussion

Far left, Cutleaf monkeyflower (Mimulus laciniatus) ordinar- ily prefers seepages on rock faces, but in 2010 individuals were found scattered in pine- needle covered duff of a recently burned forested bottomland, shown at right. These plants were likely established via seed introduced from more typical upstream sites by recent floodwaters. Such populations may only last a few years until outcompeted by other vegetation, or they may establish ite Valley – East Portion and Yosemite Arches Meadow was surveyed thoroughly permanently. Valley – West Portion maps are likely the for this special status species in 2010, but result of presumptive introductions from the habitat is now a densely vegetated higher elevations by flooding: Buxbaum’s wetland, and inappropriate for this small sedge (Carex buxbaumii), stream orchid annual plant that prefers sandy soil in (Epipactis gigantea), Northern bugleweed sun. We conclude that this population (Lycopus uniflorus), cutleaf monkeyflower was probably established in an ephemeral (Mimulus laciniatus) and lesser bladder- habitat (a sunny sandbar) from a source wort (Utricularia minor). population up Tenaya Creek and that it was extirpated due to natural succession This was also doubtless the case for the processes in a channel that was cut off Sierra sun cups (Camissonia sierrae ssp. from the main channel of Tenaya Creek sierrae) collected on a “granite sand drift” (either by natural meander processes or in Royal Arches Meadow the year after a by creation of roadbed or ditching). Sierra flood (W.L. Jepson #10478, 1924). Royal sun cups may therefore turn up again on

View of Royal Arches Meadow. Decades ago a floodchannel of Tenaya Creek with gravel bars, now a densely-vegetated seasonal wetland with a large stand of tule bulrush.

21 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

sandbars elsewhere in Yosemite Valley The flora of the valley floor was reason- left by recent or future floods. In contrast, ably well known by the end of the 19th Buxbaum’s sedge is found in most wet century, so we infer that impacts to special meadows in Yosemite Valley, at the lower status species have mostly been in the end of its known elevation in the Sierra form of extirpation of individual popula- Nevada, suggesting that it has found a suit- tions of species rather than extirpation ably cold and moist habitat in Yosemite of special status species entirely from the Valley and has become established. The valley. A case in point is the mountain primary lesson from this pattern of distri- lady slipper (Cypripedium montanum), bution is that it is important to maintain of which remain in Yosemite Valley two the flood processes (e.g., both flooding depauperate patches of plants: one patch and river meandering) in Yosemite Valley of 7 small individuals downstream of as they, in turn, maintain natural habitat Pohono Bridge and two small patches and generate species diversity. between the Curry Stables and Tenaya Creek. One of these was of two small, Adverse Impacts: Changed Hydrology non-flowering individuals, either juveniles or weak adults. The second patch had two Most of Yosemite Valley is riparian flood- individuals, one with one stem setting one plain, and, from interpretation of 19th cen- fruit, but all of the leaves of that stem had tury descriptions and photos, we under- been chewed off by deer. This section of stand that much more flooding occurred woods is converting to pine & cedar for- and much more riparian vegetation such est from oak woodland, with consequent as willow thickets covered the valley floor drying and needle accumulation on the (Ballenger, 2011 unpublished). Extensive ground. These conditions are not optimal human impacts in the form of wetland for mountain lady’s slipper and a pre- draining, such as removal of natural dams, scribed burn should be considered for this ditching and piping have been document- area. Also, the level of browsing by deer ed throughout Yosemite Valley (Ernst should be considered a potential adverse 1943, Milestone 1978) and although some impact on rare native species in Yosemite of these have since been removed, others Valley. A larger population was buried remain. The cumulative effect these im- by the Happy Isles Rockfall in 1997, and pacts has had on special status species is a a single individual near the Happy Isles reduction in the available habitat. As can boardwalk disappeared since 1980 for be seen from the Maps (Yosemite Valley – unknown reasons. Additional populations East Portion, Yosemite Valley – West Por- that may have existed in Yosemite Valley tion), most special status species sites are in earlier times went undocumented, but located in, or at the margin of, wetlands. since this species prefers shady forest at These wetland areas were more extensive the margin of wetlands, it was likely more prior to the drying and draining activities abundant prior to the drying and ‘conifer- of the past 150 years. ization’ of Yosemite Valley as a result of

Left, Buxbaum’s sedge rings a seasonal pool of water in Stone- man Meadow. Right, stream orchid thrives next to a boardwalk that replaced a social trail in Stoneman Meadow. The combination of restored hydrology that increases meadow wetness and reduction in foot traffic by hardening surfaces in high traffic areas improves habitat quickly.

22 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Results & Discussion

Left, Sierra laurel does very well as a shaded ground-cover in the Ahwahnee Hotel parking lot. Right, narrowpetal wakerobin under shrubs along the front walk of the hotel

changed hydrology. The current surviving plants. These species should not neces- patches are not thriving where they occur, sarily be discouraged from local land- as they now occupy forest with closing scaping due to their special status. The conifer canopy and drying soil. current accepted practice for producing native species is for local seeds/cuttings Hydrologic impacts are thus the greatest to be harvested by a permitted park staff threat to survival of most special status or contractor, grown out at an approved species in Yosemite Valley. An illustration nursery and brought back into the park of this point is the hydrologic restora- and planted near to the place of origin tion of flows through Happy Isles fen of the starting material. This process is which have caused Stoneman Meadow to designed to minimize movement of pests, become a wetter habitat. The two special pathogens and non-local races of natives. status species found here - Buxbaum’s Native species for landscaping should sedge (Carex buxbaumii) and stream not be placed near wild populations with orchid (Epipactis gigantea) - occupy wet which they could hybridize if they did not parts of the meadow and appear to now come from that area. The western blad- be spreading, although follow-up surveys derpod, for instance, does not occur in the will be necessary to confirm this. park closer than the Arch Rock Entrance Station. Therefore, there is no possibility Impacts of Landscaping on Special Status Species

Historically it was accepted practice to transplant wild plants to landscaping. Consequently, much of the original landscaping at The Ahwahnee and Tecoya Left, a patch of this species, in foreground behind Ranger Club, housing are natives transplanted from is likely planted. Some park elsewhere in Yosemite Valley and the special status plant species are park. A few that are park special status also excellent subjects for native plants continue to exist as landscaping at landscaping. Below, narrow-petal the Ahwahnee Hotel: Sierra laurel (Leu- wakerobin is a special status cothoe davisiae) in the visitor parking lot, species of moist, shady sites. narrow-petal wakerobin (Trillium angustipetalum) next to the front entrance walk and behind cabin #7 and western bladderpod (Staphylea occidentalis) near the swimming pool, and narrow-petal wakerobin is also found behind the Ranger Club. These species, by surviving this long, have proven to be good local landscaping

23 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

Above, wall hawkweed got established briefly between a road and a bikepath before being detected and eradicated. Right, detail of plants. Alien species arrive in Yosemite Valley at a rate of almost two new species per year.

that a planting at The Ahwahnee would This species was therefore designated a hybridize with native plants and thus this high priority invasive and quickly eradi- planting is not a problem. Developing cated by the invasive management crew. guidance for residents and park coopera- tors on best practices for native plant land- Landscaping in Yosemite Valley also pro- scaping and a suggested species list would vides an avenue of entry for non-natives. be helpful. Surveys for this project revealed a number of other worrisome non-natives in resi- Impacts of Invasive Species on Special dential areas in Yosemite Valley: stinky Status Plants Bob (Geranium robertianum), Italian lords and ladies (Arum italicum), and sweet Opportunities for introduction of non- violet (Viola odorata). These species were native species are commensurate with spreading between yards and are known the number of vectors (human, livestock, to be invasive elsewhere, so should be wildlife) coming into an area, and Yosem- monitored for spreading outside of land- ite Valley, with by far the highest visitor scaping. This has happened already in one use, consequently has the highest number case: the Ahwahnee Hotel has one speci- of non-native species of any area of the men of a weedy non-native orchid broad- park. As mentioned above, approximately leaf helleborine (Epipactis helleborine) in 1.7 new non-native plant species estab- its landscaping. This species is known to lish in Yosemite Valley every year. In the be an aggressive invader in western states course of surveys for this project, a species and surveys in nearby forested areas re- previously unknown in California, wall vealed that it had spread beyond the land- hawkweed (Hieracium murorum), a native scaping. Those plants were treated with of Europe, was observed growing in the herbicide and will be subjected to follow- Tecoya Housing area between a footpath up treatments, although there is now an and Ahwahnee Drive. This species belongs established seedbank in the vicinity of the to a genus known for aggressive weeds. Ahwahnee, so it may require re-treatment

24 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Results & Discussion

Above, candystick (Allotropa virgata) is blooming in foreground, next to pink flag. The moist habitat of forested riverbanks and old oxbow swales is the only place where this moisture-loving special status species is found. ‘Trail creep’ from high foot traffic squeezes this narrow-diameter habitat. Left, a view of the entire eight meters square patch of this plant (flags mark candystick stalks). for years. The Ahwahnee landscaping staff cal of an invasive species. At this point the agreed to remove the finished blooms species remains a ‘candidate’ for special from the plants in their landscaping before status. If proved to be native it would be the seeds matured, but the optimal solu- moved onto the special status species list. tion would be to remove the plant itself. If proved to be non-native, it would be put on the list of non-natives to be eradicated. In some cases it is unclear whether a spe- For the time being, it will be monitored. cies is native or non-native. This is the case for woolgrass (Scirpus cyperinus) which Impacts of Trampling occurs in the meadow opposite the Cha- pel. This is the only known location of this One of the significant challenges for rare species in California. The first collection flora in Yosemite Valley is trampling of was made in Yosemite Valley in 1976 by individual plants in areas which attract a J.T. Howell (52233), and the species was lot of pedestrian traffic. Replacing social listed in the Flora of California (Hickman trails with hardened surfaces such as 1993) as a non-native, since the recentness boardwalks has worked well in meadow of the first collection is taken as an indica- settings and additional locations in tion of it being newly introduced. Howev- Yosemite Valley (e.g., on the east side of er, for wetland plants, which are tradition- Ahwahnee Meadow) would benefit from ally under-collected, this is not necessarily this approach. For example, a boardwalk indicative of anything besides lack of replaced a social trail through Stoneman prior data. Botanists in Washington State Meadow which ran through a population (Peter Zika, pers. comm.) report that this of stream orchid (Epipactis gigantea). The species, also recently documented there, individuals next to or under the board- is spreading quickly into wetlands of the walk are now released from trampling Columbia River, which is behavior typi- impacts and are flourishing.

25 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

…there are two considerations which should not escape attention. First; the value of the district in its present condition as a museum of natural science and the danger – indeed the certainty – that without care many of the species of plants now flourishing upon it will be lost…Second; it is important that it should be remembered that in permitting the sacrifice of anything that would be of slightest value to future visitors to the convenience, bad taste, playfulness, carelessness, or wanton destructiveness of present visitors, we probably yield in each case the interest of uncounted millions to the selfishness of a few individuals.

– Frederick Law Olmsted, 1865.

Yosemite Valley to El Portal cies in Appendix 2). No tanoak other than that already known from the south side of The field crew, led by Heather Smith, the river opposite the junction of Highway surveyed longitudinally along both banks 140 and Big Oak Flat Road was observed. of the Merced River from Pohono Bridge (Note: On the Yosemite Valley West map, to El Portal in late September when the this point is missing.) The other special Merced River had dropped to safe levels. status species observed by the crew in this They had previous experience mapping section of river, California sunflower He( - Sierra sweetbay (Myrica hartwegii) and lianthus californicus), was observed in this other likely target species for this section same site on the sunny, sandy beach on the while working in Wawona. Immediately north side of the river. prior to the start of this survey, they were shown examples of mountain lady’s slip- The Yosemite Valley to El Portal section is per (Cypripedium montanum) and tanoak a possible location of the historic collec- (Lithocarpus densiflorus var. echinoides), tions of Sierra sweetbay and the likely lo- also known from this section of river. cation of the historic collections of Pacific yew (Taxus brevifolia) mentioned above, Results of Yosemite Valley to El Portal but these species were not discovered by Survey this survey. Western bladderpod (Staph- ylea bolanderi) was observed but not Right, Western bladderpod Sierra sweetbay was not observed on this mapped on the south bank of the Merced (Staphylea bolanderi) flowers. section of river (see discussion of this spe- River from the Arch Rock to Windy Point. Below, Western bladderpod is a small tree in moist, cool spots. Several individuals occur at the Discussion Arch Rock Entrance Station and on the south slope of the At the bottom of Yosemite Valley, the Mer- canyon from the El Portal trailer ced River flows gently for a short distance park to Cold Canyon. The lone before hurtling into a narrow granite specimen in Yosemite Valley at chasm. The river is steep and dangerous the Ahwahnee Hotel is likely a transplant. in this section, the channel cascading over large boulders, both water-smoothed and sharply-angled from recent falls. The sides of the chasm are steep and deeply shaded on the south side. There grows dense forest and enticing rocky slopes covered in mosses and flowers in the spring, but are inaccessible to botanists until the fall when the water level in the river has dropped. Few specimens are known from the south slope, most botanists having contented themselves with inspecting the

26 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Results & Discussion

area with binoculars from Highway 140. side of the river in abundance, from Arch Thus, although special status species may Rock to the Big Oak Flat junction, few well exist that are overlooked, they are other special status species had been also well-protected from human impacts reported from this side of the river in there. this section. A contributing factor to the relative lack of special status species in Although Highway 140 parallels this this river section is the high frequency of section of river and is a heavily-travelled rockfall here. Areas of active rockfall in route, relatively few travelers venture off Yosemite and in general tend to lack rare of the road in this section. Although the species - only those species sturdy enough relatively uncommon California nutmeg and fast-growing enough to survive fre- (Torreya californica) is found along this quent rockfalls remain.

27 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

The Yosemite National Park is perhaps the most delightful region in all the world for the study of plant life. The wide variety of conditions here found, ranging from the hot and dessicated slopes of the brush-clad foothills to the cold, bleak summits above timber-line, the abode of glaciers and perpetual snow, gives to the flora an exceedingly diverse and interesting character.

- Harvey Monroe Hall, 1912.

From: A Yosemite Flora.

El Portal Administrative Site nels and bottomland habitats with alluvial soils. Results of El Portal Surveys The variety of soils present in this area, in The El Portal segment of the Merced combination with dramatic variations in River was surveyed for special status moisture levels and amount of light in the species using GPS technology between two-thousand foot deep canyon of this 2003 and 2009 (Moore et al. 2010) and river segment results in a great diversity of was further surveyed for these species in plant species found within this relatively 2011. An undescribed species of Collinsia small area. For instance, the foothill veg- occurring in the El Portal Administrative etation communities find habitat at their Area has been mapped and added to the upper range limits in this area in hotter special status plant list. sites, where they grow juxtaposed with montane vegetation types in cooler sites. Discussion Thus, many foothills species have their only occurrence within the park bound- At the western park boundary, the main ary in this canyon. More importantly, fork of the Merced River emerges from the segment of the river from Parkline a narrow gorge cut deep into its granite to Briceburg is a large part of the known canyon and enters a region of metamor- range of several species endemic to this phic rock strata, primarily composed of region. These species appear to be largely Cretaceous plutonic rocks (Bass Lake or wholly restricted to metamorphic rock Tonalite) and Paleozoic sedimentary rocks formations (found here and in Kings Can- (Quartzite of Pilot Ridge) (Bateman and yon). Those which occur within El Portal Krauskopf 1987). In this section, which are: Yosemite onion (Allium yosemitense), occurs from Parkline to Briceburg, the Tompkins sedge (Carex tompkinsii), Merced River has been able to carve a Condgon’s woolly sunflower Eriophyllum( wider canyon through which it flows congdonii), Congdon’s lewisia (Lewisia with a gentler gradient, with its widest congdonii), and a new species of blue-eyed points occurring in El Portal. The highly Mary (genus Collinsia) which has not yet fractured metamorphosed rocks produce been formally published (Michael Park, steep, unstable slopes with deeper, finer- pers. comm.). These are all park special textured soils than does the granite that status species (the new Collinsia is cur- dominates upriver. Small outcrops of rently under the name Collinsia linearis) calcareous substrates and heavy metal- and the first four species are state-listed rich spring seeps are scattered through and CNPS-listed. These species all grow the area, creating a variety of habitats with within or adjacent to areas of prehistoric unusual soil chemistry. The lower gradi- and current human use. However, be- ent flows and wider channel of the river cause a large part of their habitat consists have added to the habitat complexity of of rocky ridges and slopes, little of their this section by allowing formation in this preferred habitat has been impacted section of river some braided river chan- directly. Indirect impacts to these species

28 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Results & Discussion

The unique chemistries of the local rocks combined with the steep walls near the river support a community of specialized plants. At left, a rocky overhang created by a road-cut oozes heavy-metal laden salts brightened by the green fuzz of the rare copper moss (Mieli- chhoferia elongata) (Inset). In California, copper moss is found only in the Merced River Canyon and in Kings Canyon, two places where its preferred habitat (mineralized seepages) is abundant. Yosemite does not yet assign ‘special status’ to any non-vascular plants, but rare mosses and lichens are frequent in this segment of canyon.

occur largely through encroachment by conversion. However, a portion of the invasive non-native plants, mainly an- slopes in the area are not stable enough nual grasses. Where the canyon slopes are to allow buildup of organic thatch, and in stable enough to allow these grasses to such places many native species adapted accumulate fibrous root mats and thatch to the ‘stably unstable’ talus or mineral soil that stabilize the soil further, these grasses slopes continue to survive. are able to crowd out special status species and provide sites for other invasive species The El Portal Map shows distributions to grow, furthering the cycle of habitat of special status species in El Portal. One

Congdon’s woolly sunflower (Eriophyllum congdonii) (inset) prefers steep talus slopes, both natural and man-made. For this reason, it has not had to compete with human infrastructure for most of its habitat. On Foresta Road, just upriver of the El Portal Maintenance Complex, it grows in unstable talus above and below the road, down to the river’s edge. Also in this site, a new species of blue-eyed Mary (not officially published yet) also inhabits the roadside talus. Both species are restricted to these metamorphic rock types and are found only in Mariposa County.

29 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

In foreground, Tompkins sedge fire appears to be a positive influence on (Carex tompkinsii), a state- this species as it has responded well to listed species which does very controlled burns and wildfire around El well with wildfire, is no match Portal and elsewhere. for invading groundcovers. This population of Tompkins sedge has been smothered by English The riparian vegetation of El Portal, in ivy and periwinkle spreading contrast to the slope vegetation, has been from a yard in Old El Portal. affected in larger measure by historic human use. Placement of railroad and highway corridors near the river and subsequent protection of this infrastructure from flooding have restricted the frequency and extent of rejuvenating flood cycles, changed water tables by impound- ing water flow in some areas and causing drying in others. Placement of buildings in riparian habitat has also reduced the total area of this habitat and reduced the opportunity for natural channel meander to occur.

notices first that most special status spe- Any loss of special status species in the ri- cies are found on rocky slopes and ridges. parian setting early in the development of The exception is Tompkins’ sedge, which El Portal went undocumented. Tompkins’ occurs on steep slope habitat but also sedge is the only current special status occurs in river channel forest and in the species to occur in the riparian forest set- shady slopes among houses in El Portal ting and was likely more abundant in this and Rancheria Flat. Periodic low intensity setting previously. Valley oak (Quercus

Below, an oxbow channel of the Merced River was obstructed by early development in Old El Portal. At right, the wetland downstream in this same oxbow still harbors wetland herbs and trees, but is also choked with invasive species, such as the Himalayan blackberry in the foreground.

30 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Results & Discussion

Left, native bottomland vegetation (oaks, pines, shrubs and annual herbs) was left intact to the west of the NPS Resources building erected in 2007 and it continues to flourish. Right, non-native landscaping species installed in 2007 to the east of the same building includes a lawn which requires fertilizer and supplementary watering and which has introduced non-native invertebrates (e.g., slugs and earthworms) to the site. Non-native London plane lobata) is currently under consideration tinued to its completion so that star trees (Platanus X acerifolia) for special status as it is found in a single thistle will not threaten special status are known to have interbred population in Yosemite, in El Portal. This species, such as brownies (Mimulus with native California sycamore elsewhere in California. Hybrid- oak population is discussed in the Condi- douglasii). ization with native sycamore is tion Assessment in Appendix 1. not an issue in El Portal, as the • NPS staff conduct understory burning native species is not present in Occupants and users of El Portal are do- around El Portal that reduces thatch this canyon, however the poten- ing several things that currently maintain built up by non-native grasses and pro- tial for this non-native sycamore health of special status species in the area vides for recruitment of fire-adapted to establish itself in this area is a concern. and these practices should be continued species such as Tompkins’ sedge. and expanded: • Town occupants and NPS facilities • NPS crews are removing noxious tend to leave native vegetation around weeds such as Himalayan blackberry, buildings intact and tend to minimize French broom, sweet pea and tree-of- landscaping that requires additional heaven that crowd out natives in the watering (e.g., few lawns). riparian areas. • Town occupants and NPS facili- • NPS crews have largely succeeded in ties tend to utilize native species for removing the noxious weed star-thistle landscaping purposes. NPS and town from the sunny slopes above Ranche- occupants propagate some local stock ria where it was crowding out other from seed and cuttings for local resto- species. This effort should be con- ration purposes.

31 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

Banks of heartsease and beds of cowslips and daisies are frequent, and thickets of alder, dogwood and willow often fringe the shores.”

– Frederick Law Olmsted, 1865.

Wawona of human habitation and several appear to be holding their own within the residential Results of the Surveys in Wawona area itself: Yosemite sedge (Carex sartwelliana), California sunflower Helian( - The developed areas within Wawona (the thus californicus), yellow-and-white mon- Wawona Hotel, the residential area, Camp keyflower Mimulus( bicolor), narrowpetal Wawona, Wawona golf course, and Wawona wakerobin (Trillium angustipetalum), and Campground) were surveyed over several Hall’s mules-ears (Wyethia elata). These days in July by Drs. Taylor and Colwell. Spe- can be seen in many locations. The first is cial status species occurrences were mapped likely present because residents moved it or those which were frequently encoun- from surrounding forests into their yards. tered were noted for followup surveying in The latter three appear to be species that September by field crews. The members of are fire and/or disturbance adapted, and the field crew were shown examples of each thus are pre-adapted for survival in the special status species they would encounter vicinity of human habitation. in each area and were trained on data collection, then they did gridded surveys on The South Fork of the Merced River, in their own in the residential areas, and linear the stretch that encompasses Wawona, surveys along the river course. flows over a relatively low gradient and thus displays a meandering, open chan- Discussion nel, abutted by pine-oak woodland and meadows. The substrate rock in this area In 2010, several special status species were is granite, which has decomposed into found in natural vegetation at the margins sandy gravel, creating characteristically

Hall’s mules-ears in Wawona Campground. This native species is naturally found in disturbed areas, so does well at the margins of human habitation. The upper edge of its range edges into Yosemite in Wawona.

32 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Results & Discussion

sandy bottomland. Sandy bottomland is habitation footprint area is that impacts relatively well-drained and thus seasonally on surrounding vegetation (watering, in- dry with resulting lower vegetation cover troduction of landscaping plants or lawns, in the vicinity of Wawona. Special status and trampling) are kept to a minimum by species that occur here tend to be those the occupants and users of Wawona. adapted to drier foothill habitats, finding a foothold within Yosemite’s borders in this Impacts to Special Status Species area. There are pockets of moister habitats where water flow of streamlets has built The greatest potential threat to the health up deep organic soils over millennia and of special status species populations in created wet meadows, such as the lower Wawona is competition for habitat by end of Wawona Meadow, now largely non-native species. One significant poten- under the golf course. tial source of this problem was observed while surveying the Wawona residential The benign terrain of Wawona led to its area: landscaping ornamentals have been early settlement by Galen Clark (1840). planted that have potential to or are al- Early visitors to the Mariposa “Big Tree” ready escaping from yards on private land Grove stayed at his cabin, now an aban- into surrounding park land. The park high doned site adjacent to the Wawona Golf priority weed foxglove (Digitalis purpurea) Course. Those visitors included botanists, is cultivated by several homeowners. who made botanical collections in the This species establishes easily from the area, some of which then became the ‘type many seed it produces and is the focus of specimen’ from which new species were eradication efforts in the Mariposa Grove. described. This means that the vicinity of There were also several new records for the Galen Clark Cabin is the ‘type locality’ the park of non-native species found in for several species and is therefore valued the Wawona Residential Area by this sur- by scientists as the most appropriate site to vey, some of which are worrisome: Scotch make fresh collections. Herbarium speci- broom (Cytisus scoparius), an ornamental mens from the late nineteenth century shrub which is a noxious weed in other that are merely labeled “Clark’s cabin” are western states is producing offspring on inferred to come from the Wawona area. land adjacent to some homes in Wawona. Common bugle (Ajuga reptans), a mint- The benign environment of this area family ground cover herb native to Europe also attracted various subsequent human and escaped from cultivation throughout uses (orchards, cattle range, air landing the United States, was found adjacent to strip) that continue today in the form of a one home in Wawona. Common bugle residential area, summer camp complex, is not yet reported as established in hotel complex and golf course. Continu- California, but it reproduces vigorously ous human occupation has led to reduc- from lateral roots and its proximity to the tion in meadow and riparian habitat, and Merced River provides an opportunity for could possibly have led to the extirpation it to spread through the river system. Yel- of some special status species, but none can be confirmed from comparison of historical records with extant species lists. Historical records do suggest that mountain ladyslipper (Cypripedium montanum) occurred at several additional sites in Wawona to what is known today and that it may have been negatively affected by il- legal collecting in the early 20th century. The non-native English daisy The major contributing factor to survival is a weed in the Wawona Golf of these species within the ongoing human Course lawn.

33 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

Left, special status species yellow-and-white monkeyflower does well at the forested west margin of the golf course where a recent prescribed burn occurred. Right, narrowpetal wakerobin patches behind the ‘rough’ in shaded spots kept clear of brush on the west side of the golf course.

lowflag iris Iris( pseudacoris) is a wetland in Yosemite was found on fairway 2. The ornamental, a native of Eurasia and Africa, marsh meadow foxtail grass (Alopecurus that is known to be invasive in eastern geniculatus), a native of Europe was found U.S. wetlands. It appears to have been in wet areas of the fairways; catnip (Nepe- planted in a stream drainage by a home- ta cataria), an aggressively spreading me- owner in Wawona. Finally, Oregon-grape dicinal herb, was found in the unmowed (Berberis aquifolia) has been planted by margin between the golf course and the several homeowners and is establishing river. A species list for the golf course was itself up and down drainages in Wawona. provided to the golf course staff and is This plant is marketed by nurseries as a found in Appendix 4. The golf course staff California native plant but is not native to is already doing spot removal of non-na- the Sierra Nevada. Its Sierra Nevada natives that they recognize, but a cooperative tive relative, California barberry (Berberis invasive management plan would focus dictyota) occurs naturally downstream time and effort efficiently and reduce the of Wawona in the river channel but has chances of other non-natives arriving by not been utilized as a landscaping plant this entry point. The golf course staff, by in Wawona itself. Resident education keeping brush cleared at the margin of the on risky landscape plantings would go a course, are maintaining habitat for special long way towards solving this problem. status species narrowpetal wakerobin and A “Good Neighbor” handbook that sets yellow-and-white monkeyflower, both of out horticultural guidance & resources for which were found there in 2010. park residents and neighbors is becoming a common practice for land management The location of the historic site of the agencies with urban neighbors. For park Wawona Arboretum (built by the 9th Cav- partners, a more interactive approach alry) at the confluence of Big Creek and would be warranted, e.g., working more the South Fork Merced River was investi- closely with park concessions to develop gated. Documents describing this project a list of attractive local native landscaping suggested that the arboretum consisted of plants and one for those to be avoided. infrastructure and signage posted on existing vegetation only and that the project The golf course is also a potential point was abandoned before exogenous plants source of non-natives for this area. The were transplanted to the site. A ground following new records for the park were verification concurred that although rem- found in the course of this survey: English nants of infrastructure still exist at the site, daisy (Bellis perennis), a European weed no non-native or unusual native species common in lawns but otherwise unknown occur at the site.

34 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Bibliography

Bibliography

Acree, L., D. Grossenbacher, and A. E. L. Consortium of California Herbaria. 2011. Colwell. 2007. Special status plants in Data provided by the participants of the Tuolumne River Corridor. Unpub- the Consortium of California Herbar- lished report produced by the Division ia (http://www.ucjeps.berkeley.edu/ of Resources Management and Sci- consortium) ence, Yosemite National Park. Ernst. E. F. 1943. Preliminary report on Anderson, M. K. 2005. Tending the wild: the study of the meadows of Yosemite Native American knowledge and the Valley. Unpublished report for Yosem- management of California’s natural re- ite National Park, California. sources. University of California Press, Gaines, D. A. 1980. The valley riparian Berkeley, California. forests of California: their importance Ballenger, L., L. Acree, K. Wilkin, J. Bac- to bird populations. Pages 57–85 in cei, T. Whittaker, and E. Babich. 2011. Sands, A., editor. Riparian forests in 2010 Assessment of meadows in the California: their ecology and conserva- Merced River corridor, Yosemite tion. Symposium proceedings, May 14, National Park. Unpublished report 1977; Davis, CA. University of Califor- produced by the Division of Resources nia, Division of Agricultural Sciences, Management and Science, Yosemite Davis, California. National Park. Glazner, A. F., and G. M. Stock. 2010, Ge- Bateman, P. C., and K. B. Krauskopf. 1987. ology underfoot in Yosemite National Geologic map of the El Portal quad- Park and vicinity. Mountain Press rangle, west-central Sierra Nevada, Publishing Co., Missoula, Montana. California. U.S.G.S. Miscellaneous Hall, H. M. 1912. A Yosemite Flora. Paul Field Studies Map MF-1998. Elder & Company, San Francisco, Bornstein, A. J. 1997. Myricaceae – Wax- California. myrtle Family. Vol. 3. Flora of North Hehnke, M., C. P. Stone. 1979. Value of ri- America Editorial Committee, eds. parian vegetation to avian populations 1993+. Flora of North America north along the Sacramento River system. of Mexico. 12+ vols. New York and Pages 228–235 in Johnson, R. R., and J. Oxford. F. McCormick, technical coordinators. Brandegee, K. 1891. The flora of Yo Sem- Proceedings of the symposium on the ite. Zoe 2:155–167. strategies for protection and manage- Brewer, W. H. 2003. Up and down Califor- ment of floodplain wetlands and other nia in 1860–1864: the journal of Wil- riparian ecosystems, December 11–13, liam H. Brewer. Fourth edition, with 1978, Callaway Gardens, Georgia. maps. University of California Press, USDA Forest Service General Techni- Berkeley, California. cal Report WO-12. Washington, DC. California Native Plant Society. 2011. Inven- Hickman, J. C., editor. 1993. The Jepson tory of rare and endangered plants of manual: higher plants of California. California, online edition (http://www. University of California Press, Berke- cnps.org/cnps/rareplants/inventory). ley, California. Colwell, A. E. L., C. J. Sheviak, and P. House, M. A., B. P. Wernike, and K. A. E. Moore. 2007. A new Platanthera Farley. 1998. Dating topography of the (Orchidaceae) from Yosemite National Sierra Nevada, California, using apatite Park. Madroño, Vol. 54(1):86–93. (U-Th)/He ages. Nature 396:66–69. Colwell, A. E. L. 2010. Unusual lake floras House, M. A., B. P. Wernike, and K. A. of Yosemite National Park. Unpub- Farley. 2001. Paleo-geomorphology lished report produced by the Division of the Sierra Nevada, California, from of Resources Management and Sci- (U-Th)/He ages in apatite. American ence, Yosemite National Park. Journal of Science 301:77–102.

35 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

Howard, J. L. 1992. Quercus lobata. In Fire Yosemite Association, Yosemite Na- Effects Information System, [Online]. tional Park, 1993. USDA Forest Service, Rocky Moun- Rossi, R. S. 1980. History of cultural tain Research Station, Fire Sciences influences on the distribution and Laboratory. Available: http://www. reproduction of oaks in California. fs.fed.us/database/feis/ [accessed Janu- Pages 7–18 in Plumb, T. R., technical ary 19, 2011]. coordinator. Proceedings of the sym- Huber, N. K. 1989. The geologic story posium on the ecology, management of Yosemite National Park. Yosemite and utilization of California oaks, Association, Yosemite National Park, June 26–28, 1979, Claremont, CA. California. USDA Forest Service Pacific South- Jepson, W. L. 1909. The trees of California. west Region Publication Gen. Tech. Cunningham, Curtis & Welch. Rep. PSW-44. Law, J. 1993. Memories of El Portal. Mari- Sawyer, J.O., T. Keeler-Wolf, and J.M. posa Heritage Press. Mariposa, CA. Evens. 2009. A manual of California McClaran M. 1986. Age structure of Quer- vegetation. Second edition. Califor- cus douglasii in relation to livestock nia Native Plant Society, Sacramento, grazing and fire. PhD dissertation, California. University of California, Berkeley. Small, E. E. and R. S. Anderson. 1995. Milestone, J. F. 1978. The influence of Geomorphically driven Late Cenozoic modern man on the stream system in rock uplift in the Sierra Nevada, Cali- Yosemite Valley. Master’s thesis, San fornia. Science 270:277–280. Francisco State University, San Fran- Stock, G. M., R. S. Anderson, and R. C. cisco, California. Finkel. 2004. Pace of landscape evolu- Moore, P. E. 2004. Special status vascular tion in the Sierra Nevada, California, plant list for Yosemite National Park. revealed by cosmogenic dating of cave Unpublished report prepared for the sediments. Geology 32(3):193–196. National Park Service by the USGS. Stock, G. M., R. S. Anderson, and R. C. Moore, P. E., A. E. L. Colwell, and D. Finkel. 2005. Rates of erosion and Grossenbacher. 2007. Rare plant sur- topographic evolution of the Sierra veys in unusual habitats of Yosemite Nevada, California, inferred from National Park, California, 2005 and cosmogenic 26Al and 10Be concen- 2007. Unpublished report prepared trations. Earth Surface Processes and for: The Yosemite Fund, San Fran- Landforms 30:985–1006. cisco, California and National Park Tyler, C., B. Kuhn, and F. Davis. 2006. De- Service, Yosemite National Park by mography and recruitment limitations the USGS. of three oak species in California. The Moore, P. E., A. E. L. Colwell, and C. L. Quarterly Review of Biology 81(2). Coulter. 2010. Special status vascular U.C. Davis 1996, Sierra Nevada ecosystem plant surveys and habitat modeling in project, final report to Congress vol. Yosemite National Park, 2003–2004. 1: assessment summaries and manage- National Park Service, Fort Col- ment strategies. lins, Colorado. Natural Resource Wernike, B., R. Clayton, M. Ducea, C.H. Technical Report, NPS/SIEN/ Jones, S. Park, S. Ruppert, J. Saleeby, NRTR—2010/389. J. K. Snow, L. Quires, M. Fliedner, G. Mulch, A., S. A. Graham, C. P. Chamber- Jiracek, R. Keller, S. Klemperer, J. Lu- lain. 2006. Hydrogen isotopes in Eo- etgert, P. Malin, K. Miller, W. Mooney, cene river gravels and paleoelevation of H. Oliver, and R. Phinney. 1996. Origin the Sierra Nevada. Science 313:87–89. of high mountains in the continents: Olmsted, F. L. 1865. Yosemite and the the southern Sierra Nevada. Science Mariposa Grove: a preliminary report. 271:190–193.

36 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Appendix 1

Appendix 1

Condition Assessment of Valley River Canyon, with the nearest population Oaks (Quercus lobata) in El Portal to the west occurring at Indian Flat 3 miles to the west, a few more scattered down- Background stream in the Merced River Canyon and most populations occurring in the Central Valley oak (Quercus lobata) is a keystone Valley 50 miles to the west. tree species in floodplain riparian habitats of California. Its presence is tied to a high The nucleus of the El Portal valley oak water table, as valley oaks occur where population is the El Portal Road, located the water table is 30 m deep or less (Tyler adjacent to the existing fuel storage facility 2006). Endemic to California, valley oak and El Portal Post Office. The population populations have experienced a wide- extends west in the floodplain to Middle spread decline throughout the state. This Road, and east in the river cut-off channel decline is due primarily to loss of habitat, toward the gas station. Additional oaks and similar declines have been observed occur a short distance up the hillside in El for many low elevation native species, as Portal, though botanists suspect that the foothill areas below about 3,300 feet have oaks in these drier uphill habitats could be experienced the greatest loss of ripar- hybrids between valley oaks and adjacent ian vegetation of any region in the Sierra upland oak species (a common phenom- Nevada (U.C. Davis 1996). The California enon in oaks). These upland oaks exhibit Native Plant Society has listed the valley slight differences in morphological char- oak plant community, or Quercus lobata acteristics from the core population, such Alliance, as rare and threatened through- as slightly hairy terminal buds, although out its range (Sawyer et al. 2009). genetic studies have not been done to confirm a hybrid status. These drier-habitat Valley oak riparian and woodland areas oaks are not part of the population that comprise critical habitat of high value to is an outstandingly remarkable value, as wildlife (Howard 1992). In general, ripar- they are not strongly river-dependent or ian environments support more species river-related. and greater numbers of wildlife than any other habitat type in the Sierra Nevada Condition at the time of 1987 designation (U.C. Davis 1996). Collectively, valley oak riparian forests in California support Anderson (2005) estimated that urbaniza- 67 nesting bird species- more than any tion and land conversion destroyed about other California habitat for which data are 90% of valley oak stands in California that available (Gaines 1980). The ecological existed prior to European contact. In the Two views of 1913 El Portal significance of riparian habitat at lower Sacramento River System, researchers flood in core valley oak habitat. elevations in Yosemite is accentuated by estimate that about 1.5 percent of original (Law 1993). its Mediterranean climate, where water valley oak acreage remains (Hehnke 1979). is extremely limited during hot summer months. In the Merced River Can- yon, valley oaks provide forage for deer, acorns for birds, rodents and bears, and food storage and nesting sites for acorn woodpeckers.

Yosemite is home to one valley oak population, located at the El Portal Administra- tive Site. This population lies at the eastern boundary for the species in the Merced

37 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

Left, vehicular traffic within dripline of a tree will compact soil and possibly injure trees. Right, a recently fallen valley oak was in the 80–100 cm dbh size class and was 117 years old when it died. (Photo on left by Mike Osborne.)

The valley oak population in El Portal was The core El Portal valley oak population an exception to this extensive loss, though contains 38 individual trees, with sizes the population did sustain moderate im- ranging from 1-140 cm diameter at breast pacts from rural development such as the height (see Figure 1). Five valley oaks construction of the terminus of the Yosem- in the smallest size class were removed ite Valley Railroad in El Portal in the 1930s. within the past five years during a resto- ration project, and are thus not reflected Current Condition: Oak researchers in the figure. The distribution of the El use four traditional methods to evalu- Portal valley oak population in a variety ate the condition and structure of oak of age classes, with more young trees woodlands—age structure, size structure, than old trees, is of particular impor- comparative analysis of historic and cur- tance. The greatest problem facing those rent photos, and comparative analysis of who manage valley oak woodlands is lack on-the-ground surveys. Each method has of sapling recruitment (Howard 1992). limitations and merits. One of the most In a review of published studies on the useful tools to examine the condition and demography and recruitment of Califor- long-term viability of the El Portal valley nia oak trees, nearly all of the valley oak oak population is the size distribution of inventories found valley oak seedlings existing individual trees (Tyler 2006). While and saplings to be uncommon or absent the size of oaks does not necessarily reflect (Tyler 2006). The El Portal population is the age of oaks, it is generally true that the exemplary in that it contains a relatively largest individuals are probably old and the well-rounded distribution of age-classes. youngest individuals are generally small, but it is not always the case that the smallest Local development continues to limit val- trees are young. Regardless, the size of oaks ley oak establishment in potential habitat is a good indicator of reproductive capa- in El Portal. The unpaved parking lots bilities (Tyler 2006). A healthy population across Foresta Road from the railroad would generally have all size classes pres- engine have expanded under the drip line ent, but would have a higher number of of mature oaks, some areas within the smaller individuals than larger individuals. core oak population have been graded,

38 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Appendix 1

Figure 1. Size class distribution of core valley oak population in dbh (diameter at breast height). [Note: Five trees in the smallest size class are not reflected in this figure, as they were removed in the last five years.]

and small numbers of young oaks have from neighbors. Mature trees are sensitive been removed for a variety of reasons. The to over watering, pruning, grade changes, valley oak understory is in some places and asphalt covering the root system (Ros- kept clear of understory vegetation that si 1908). In El Portal, long-term stability would protect young trees from browsing of the valley oak population would be or trampling. Also, an invasion of non- enhanced by protection of habitat in the native Himalayan blackberry makes much vicinity of valley oak trees and especially understory area inhospitable for seedling under the drip line of existing oak trees, recruitment. Despite these issues, the core removal of invasive plants and protection population retains sufficient integrity as (from browsing by deer and from mow- a vegetation community, and is classified ing) with stakes and wire cloth tubes, and as valley oak woodland in the park wide cultivation of new recruits. vegetation map for Yosemite. A significant requirement for survival of As summarized by McClaran (1986), this population of valley oaks, a high water successful oak recruitment requires a table, continues to be met in El Portal as combination of events including abundant the root systems of mature oaks are likely acorn production, sufficient rainfall, and connected to the Merced River water limited competition for light and water table, which remains stable.

39 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

Appendix 2

Condition Assessment of Sierra most closely related to bog myrtle (Myri- Sweetbay (Myrica hartwegii) in ca gale), a circumboreal species whose Wawona range extends only as far south as the Cascade Mountains of Washington and Sierra sweetbay (Myrica hartwegii A. Oregon. These two species would likely Chevalier) is a shrub in the myrtle family have diverged as a result of isolation from (Myricaceae), a small family of shrubs and each other caused by glaciation or volca- small trees, found in both temperate and nic events. tropical regions, which typically contain aromatic resins. Sierra sweet bay is no ex- The California Native Plant Society listed ception - rubbing the leaves between the Sierra sweet bay on its Inventory of Rare fingers releases a spicy odor, an excellent and Endangered Plants in 2010, with an field identification clue. The myrtle fam- assigned rarity level of 4.3. The 4 indi- ily is neither large nor prominent in our cates ‘limited distribution (Watch List)’, flora, it is represented in North America given because of the restricted area within by only two genera, the monospecific which this species occurs (El Dorado, sweet-fern (Comptonia peregrina) in the Madera, Mariposa, Tuolumne Counties eastern U.S. and by seven Myrica species only) and because it has been documented across the U.S., two of which occur in from fewer than ten drainages within that California: California wax-myrtle (Myrica area. The 0.3 indicates ‘not very endan- californica), found from Washington state gered in California’, and is given because through the Coast Ranges of California, most known populations receive some and Sierra sweet bay, which is found only sort of protection on public land and in the central Sierra Nevada (Bornstein those on private land are not threatened 1997). Sierra sweetbay appears to be by large-scale development. (CNPS 2011)

Sierra sweetbay, along with Indian rhubarb, thrives in a boulder-filled side channel of the South Fork, away from the main current.

40 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Appendix 2

Sierra sweetbay lines a straight segment of river at the normal high water line n here.

Two of the known occurrences are partly vey for this species, conducted in July in Yosemite National Park: 1) the Big and September 2010, confirmed that it Creek population that follows Big Creek continues to occur in much of its histori- from Fish Camp (Sierra National Forest) cally documented range, as an intermit- to its confluence with the South Fork of tent stand consisting of several hundred the Merced River and from there down individuals, along Big Creek from where the South Fork possibly as far as the con- Big Creek enters the park near the South fluence with the main stem of the Merced Entrance Station to the mouth of Big River (see Wawona Map and Wawona Creek at the Merced River. It continues Campground Map), and 2) the South Fork from this confluence downstream on the of the Tuolumne River population that be- South Fork to nearly the park bound- gins some miles upstream of the western ary, and possibly occurs beyond the park park boundary in Yosemite and crosses boundary, although surveys for this study into the Stanislaus National Forest, did not include areas outside the park. continuing downstream for an unknown Sierra sweet bay was not observed to distance. With these two populations, occur on the South Fork of the Merced Yosemite contains a significant portion of River upstream of the mouth of Big Creek the known range and known populations to the wilderness boundary upstream of of this species. Wawona. The lack of its occurrence in this section is possibly due to its not hav- Existing Documentation ing been able to colonize upstream from Big Creek. The stretch of river upstream Sierra sweet bay has been very well of Wawona to the wilderness boundary documented over time within Yosemite appears to be similar habitat to that which and herbarium records have been made occurs from the Wawona Campground throughout its occurrence on the South downstream, yet Sierra sweet bay has not Fork of the Merced River (Consortium be observed there. The stretch of river of California Herbaria 2011). The sur- in the vicinity of Wawona itself appears

41 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

Above right, are female inflores- botanist caused us to survey for this spe- cences, the fruits beginning to cies on the main stem of the Merced River ripen in the fall. Below are male from the lower end of Yosemite Valley to catkins, dried up and detached from the plant in early summer El Portal. However, we did not find Sierra after pollen has been released, sweet bay in the main stem of the Merced caught on a branch near a pair River. It could occur below the confluence immature cone-like female of the main stem and with the South Fork inflorescences. Note differences at Savage’s Trading Post in the Stanislaus in leaf shape between these two National Forest, which would also fulfill individuals. the Brandegee location description, but was not surveyed for in that location for this report. Therefore it cannot currently be discerned from historic records as to whether Sierra sweet bay never occurred on the main stem of the Merced River within the park boundary, or was extirpated from that section. Our observations suggest that this species prefers protected banks along third order streams which contain large boulders and shaded shore- lines. In contrast, the section of the main sunnier and sandier than the habitats in stem of the Merced River immediately which this species is found, so is perhaps below Yosemite Valley is high volume, and not optimal habitat for this species. it fluctuates in flow height a great deal, leaving the shady, boulder-dense banks far In The Flora of Yo Semite, Katherine Bran- from the water’s edge in late summer. It degee states “Myrica hartwegi, a rather rare appears to not be the preferred habitat for wax-myrtle, though not found in the valley Sierra sweet bay, so if Sierra sweet bay did grows on the Merced below it” (Brandegee occur here at one time, it did not likely oc- 1891). This historic report by a respected cur in large numbers.

42 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Appendix 2

A hazard tree was felled onto Sierra sweetbay plants. The bushes will likely just grow up around it, unless floods cause scouring to wash individuals away on the upstream side.

Sierra sweetbay is a deciduous (loses its flowering shrub. Its flowers are not showy leaves in winter) and dioecious (individual because it is wind-pollinated. Its fruits plants are either male or female) summer- offer no obvious reward to animals, so are

A Sierra sweetbay was cut away with a machete or axe, presum- ably by a camper wishing to access the water.

43 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

Foot traffic is the major ongoing effect in the vicinity of the Wawona Campground. Other segments of this species’ habitat are minimally affected by human traffic. At right, dense footprints texture a sandbar downstream of Wawona Camp- ground, surrounding a patch of small Sierra sweetbay stems.

likely dispersed by physical means, such prevalent. Individual clones, when growing as water currents. It is strictly riparian, intermixed in a large thicket, could be dis- found only along stream and small river tinguished from each other by the flower borders at the normal high water mark sex and by individual variation in the shape from about 250-1800 m. and color of the leaves and the stature of the shrub. Seed set was not assessed. Dioecious wind-pollinated species are particularly vulnerable to reproductive Current Condition of the Habitat problems if populations fall too low. This is because male and female plants must be Big Creek has had a significant portion of in sufficient proximity that wind can trans- its flow diverted upstream from the park, port pollen between them. If the distance according to the Madera County General between males and females is great, or Plan, which states: the sex ratio in a given spot is too skewed toward one of the sexes, then the amount Merced River flows in the amount of of the seed crop will drop. It is clear that 6,000-acre feet a year into Lewis Creek, within Yosemite, Sierra sweet bay individu- a tributary of the Fresno River. Madera als expand vegetatively by spreading under- Irrigation District’s Big Creek (50 cfs) ground rootstocks, often developing very diversion to Lewis Creek is based on large clones (5 meters or more diameter) water rights for the Madera Canal of a single sex. It is possible that pieces of and Irrigation Company. The water is the roots or stems can function as vegeta- diverted December 1st – July 15, begin- tive propagules when washed downstream, ning with 50 cfs in Big Creek, which is as is the case with willows and poplars, reduced to 20 cfs by April. The diver- but this is unconfirmed for Sierra sweet sion is set in November. In dry years, bay. During our survey of the Wawona the water is released down Big Creek. population, we found that there was rough parity between males and females overall This water diversion has an unknown in the population, with slight local disparity effect on the Sierra sweet bay, but may be

44 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Appendix 2

Bay thrives in close proximity to the campground where the riverside is less attractive to bathers.

neutral or beneficial in that it keeps stream the campground the stems of a Sierra flows more even, reducing flood scour of sweetbay individual were cut with a the creek banks. The specific effects of sharp implement. One instance of a flooding on habitat or dispersal of Sierra hazard tree felled on top of some Sierra sweet bay have not been studied. sweetbay individuals was also observed. However, these impacts do not sum Surveys of Sierra sweetbay in the vicinity to a significant adverse effect on the of the Wawona Campground revealed a population. low level of adverse effect from human impact. The most frequent and ongoing The overall condition of Sierra sweet bay impact is foot traffic, as social trails are on the South Fork of the Merced River in worn through its habitat along the river, Yosemite National Park is of a large and and sandbars attract distributed foot thriving population. There is no reason to traffic. Other adverse effects observed believe that it has not remained more or in September 2010: just downstream of less in its natural condition.

45 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

Appendix 3

Yosemite Special Status Plants Documented in Merced River Corridor

FAMILY SCIENTIFIC NAME STATE STATUS CNPS STATUS PARK STATUS ELEV L ELEV H HABITAT TYPE Aristolochiaceae Asarum lemmonii SSP 1100 1900 Shady wet places along creeks, north-facing river banks; Yosemite Valley, Wawona Asteraceae Eriophyllum congdonii Listed 1B SSP 500 1900 Sunny rockys slopes on metamorphic talus; next to river in El Portal Asteraceae Helianthus californicus SSP 1600 2000 Meadows, seeps, streambanks, seasonally inundated areas; Wawona Asteraceae Hulsea heterochroma SSP 300 2500 Chaparral, openings in yellow pine forest, Yosemite Valley, 5 miles above Nevada Fall Asteraceae Senecio clarkianus SSP 1400 2700 Damp montane meadows; Wawona Asteraceae Wyethia elata 4 SSP 1000 1400 Open woodland, forest; Wawona Boraginaceae Plagiobothrys torreyi var. 1B SSP 1200 3400 Moist meadows and flats, forest edges; Yosemite Valley torreyi Cyperaceae Bulbostylis capillaris 4 SSP 1000 2000 Meadows and seeps, meadow habitats, vernally moist gravel pans; Yosemite Valley Cyperaceae Carex buxbaumii 4 SSP 1200 3300 montane and subalpine fens ; Coastal Prairie, Yellow Pine Forest, Red Fir Forest, Lodgepole Forest, Subalpine Forest, Meadows and seeps , wet conditions in meadow habitats. Yosemite Valley Cyperaceae Carex canescens SSP 1000 3200 Lake margins, drainages in wet meadows; historic collection from Clark’s Wawona Cyperaceae Carex fissuricola SSP 1500 3500 Meadow slopes and flats, among rocks, wet areas, spray zones; Nevada Falls Cyperaceae Carex sartwelliana SSP 1200 2600 Moist forest openings and meadow borders; Wildcat Creek Cyperaceae Carex tompkinsii 4 SSP 1200 1800 Canyon slopes and river bottomlands under conifer-oak woodland canopy; El Portal area Ericaceae Leucothoe davisiae SSP 1300 2600 Moist, shaded drainage bottoms along creeks and rivers; Yosemite Valley Ericaceae Vaccinium parvifolium SSP 1400 2500 Moist, shaded drainage bottoms along creeks and rivers; Merced River Wawona area Fagaceae Lithocarpus densiflorus SSP 600 2000 Dry shady forest conditions in slope habitats; Merced River below Yosemite Valley var. echinoides Fagaceae Quercus lobata SSP 720 Deep soil on slopes and in valleys. Known from a few majestic specimens in El Portal. Hippuridaceae Hippuris vulgaris SSP 0 2600 Lakes, ponds, springs, rivers. Little Yosemite Valley Hydrophyllaceae Phacelia tanacetifolia SSP 1000 2000 Habitat variable, occurs in slope habitats; Bridalveil Falls, Yosemite Valley Isoetaceae Isoetes occidentalis SSP 1500 2500 Mountain lakes and rivers; In Merced River Little Yosemite Valley Lamiaceae Lycopus uniflorus 4 SSP 1600 2000 Moist areas, marshes, near springs; Merced River banks from El Portal up Lamiaceae Scutellaria bolanderi ssp. SSP 300 2000 Gravelly soils, stream & riverbanks, meadows in oak or pine woodland; Wawona bolanderi Liliaceae Erythronium SSP 1500 2700 Open forests, meadows, rocky places; Yosemite Valley - possibly extinct purpurascens Liliaceae Narthecium californicum SSP 700 2600 Fens, seeps; occurs under wet conditions by streams and waterfalls; Bridalveil Falls Liliaceae Trillium angustipetalum SSP 100 2000 Shaded bottomlands; Wawona, Yosemite Valley Myricaceae Myrica hartwegii SSP 300 1500 Stream and riverbanks; Along Merced below Wawona Onagraceae Camissonia sierrae ssp. 1B SSP 2000 2350 On vernally moist gravel and sand pans; Merced Lake alticola Onagraceae Camissonia sierrae ssp. 4 SSP 500 1300 Granite gravel seepage areas; Yosemite Valley sierrae Orchidaceae Cypripedium montanum 4 SSP 200 2200 Deep humus and shade of canyon bottoms; Wawona & below Yosemite Valley Orchidaceae Epipactis gigantea SSP 1500 2600 Moist conditions in meadows, streambank habitats & cliff basins; Yosemite Valley Orchidaceae Piperia colemanii 4 G3 1200 2300 Chaparral, lower montane coniferous forest. Little Yosemite Valley 46 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Appendix 3

Appendix 3

Yosemite Special Status Plants Documented in Merced River Corridor

FAMILY SCIENTIFIC NAME STATE STATUS CNPS STATUS PARK STATUS ELEV L ELEV H HABITAT TYPE Aristolochiaceae Asarum lemmonii SSP 1100 1900 Shady wet places along creeks, north-facing river banks; Yosemite Valley, Wawona Asteraceae Eriophyllum congdonii Listed 1B SSP 500 1900 Sunny rockys slopes on metamorphic talus; next to river in El Portal Asteraceae Helianthus californicus SSP 1600 2000 Meadows, seeps, streambanks, seasonally inundated areas; Wawona Asteraceae Hulsea heterochroma SSP 300 2500 Chaparral, openings in yellow pine forest, Yosemite Valley, 5 miles above Nevada Fall Asteraceae Senecio clarkianus SSP 1400 2700 Damp montane meadows; Wawona Asteraceae Wyethia elata 4 SSP 1000 1400 Open woodland, forest; Wawona Boraginaceae Plagiobothrys torreyi var. 1B SSP 1200 3400 Moist meadows and flats, forest edges; Yosemite Valley torreyi Cyperaceae Bulbostylis capillaris 4 SSP 1000 2000 Meadows and seeps, meadow habitats, vernally moist gravel pans; Yosemite Valley Cyperaceae Carex buxbaumii 4 SSP 1200 3300 montane and subalpine fens ; Coastal Prairie, Yellow Pine Forest, Red Fir Forest, Lodgepole Forest, Subalpine Forest, Meadows and seeps , wet conditions in meadow habitats. Yosemite Valley Cyperaceae Carex canescens SSP 1000 3200 Lake margins, drainages in wet meadows; historic collection from Clark’s Wawona Cyperaceae Carex fissuricola SSP 1500 3500 Meadow slopes and flats, among rocks, wet areas, spray zones; Nevada Falls Cyperaceae Carex sartwelliana SSP 1200 2600 Moist forest openings and meadow borders; Wildcat Creek Cyperaceae Carex tompkinsii 4 SSP 1200 1800 Canyon slopes and river bottomlands under conifer-oak woodland canopy; El Portal area Ericaceae Leucothoe davisiae SSP 1300 2600 Moist, shaded drainage bottoms along creeks and rivers; Yosemite Valley Ericaceae Vaccinium parvifolium SSP 1400 2500 Moist, shaded drainage bottoms along creeks and rivers; Merced River Wawona area Fagaceae Lithocarpus densiflorus SSP 600 2000 Dry shady forest conditions in slope habitats; Merced River below Yosemite Valley var. echinoides Fagaceae Quercus lobata SSP 720 Deep soil on slopes and in valleys. Known from a few majestic specimens in El Portal. Hippuridaceae Hippuris vulgaris SSP 0 2600 Lakes, ponds, springs, rivers. Little Yosemite Valley Hydrophyllaceae Phacelia tanacetifolia SSP 1000 2000 Habitat variable, occurs in slope habitats; Bridalveil Falls, Yosemite Valley Isoetaceae Isoetes occidentalis SSP 1500 2500 Mountain lakes and rivers; In Merced River Little Yosemite Valley Lamiaceae Lycopus uniflorus 4 SSP 1600 2000 Moist areas, marshes, near springs; Merced River banks from El Portal up Lamiaceae Scutellaria bolanderi ssp. SSP 300 2000 Gravelly soils, stream & riverbanks, meadows in oak or pine woodland; Wawona bolanderi Liliaceae Erythronium SSP 1500 2700 Open forests, meadows, rocky places; Yosemite Valley - possibly extinct purpurascens Liliaceae Narthecium californicum SSP 700 2600 Fens, seeps; occurs under wet conditions by streams and waterfalls; Bridalveil Falls Liliaceae Trillium angustipetalum SSP 100 2000 Shaded bottomlands; Wawona, Yosemite Valley Myricaceae Myrica hartwegii SSP 300 1500 Stream and riverbanks; Along Merced below Wawona Onagraceae Camissonia sierrae ssp. 1B SSP 2000 2350 On vernally moist gravel and sand pans; Merced Lake alticola Onagraceae Camissonia sierrae ssp. 4 SSP 500 1300 Granite gravel seepage areas; Yosemite Valley sierrae Orchidaceae Cypripedium montanum 4 SSP 200 2200 Deep humus and shade of canyon bottoms; Wawona & below Yosemite Valley Orchidaceae Epipactis gigantea SSP 1500 2600 Moist conditions in meadows, streambank habitats & cliff basins; Yosemite Valley Orchidaceae Piperia colemanii 4 G3 1200 2300 Chaparral, lower montane coniferous forest. Little Yosemite Valley 47 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

Yosemite Special Status Plants Documented in Merced River Corridor

FAMILY SCIENTIFIC NAME STATE STATUS CNPS STATUS PARK STATUS ELEV L ELEV H HABITAT TYPE Poaceae Cinna bolanderi 1B SSP 1670 2440 Montane stringer meadows and fens; Wawona & Little Yosemite Valley Poaceae Glyceria borealis SSP 800 1250 Marshes and shallow lake borders; Yosemite Valley Portulacaceae Lewisia congdonii Listed 1B SSP 500 2800 Lower montane coniferous forest, metamorphic cliffs; El Portal Potamogetonaceae Potamogeton epihydrus 2 SSP 400 1900 Freshwater marshes, tanks; Yosemite Valley ssp. nuttallii Saxifragaceae Bolandra californica 4 SSP 2000 3000 Lower and upper montane coniferous forest, mesic, rocky shaded places; Lyell Fork Merced River Saxifragaceae Saxifraga mertensiana SSP 1000 2500 Mossy rocks, cliffs; Yosemite Valley Saxifragaceae Saxifraga oregana SSP 150 2500 Meadows and seeps; occurs under wet conditions in meadow habitats; Yosemite Valley & Little Yosemite Valley Scrophulariaceae Antirrhinum leptaleum SSP 300 2100 Small washes, shallow ditches, disturbed areas, in foothill woodland, yellow pine forest; historic collection from Wawona Scrophulariaceae Collinsia linearis SSP 200 2000 Rocky, metamorphic substrates of broad-leaved upland forest, chaparral, cismontane woodland; El Portal & Wawona Scrophulariaceae Cordylanthus rigidus ssp. 4 SSP 1100 2500 North side Yosemite Valley, dry sandy roadside full sun, 1 mi E Cascade Creek Sharsmith brevibracteatus 6465 8 Sept 1957 Scrophulariaceae Lindernia dubia var. SSP 500 1600 Exposed margins of lakes and ponds, mudflats; Yosemite Valley anagallidea Scrophulariaceae Mimulus bicolor SSP 360 2100 Occurs under vernally moist conditions; usually in nonwetlands, but occasionally found on wetlands & river bottomlands; Wawona Scrophulariaceae Mimulus inconspicuus 4 SSP 160 2000 Chaparral, cismontane woodland, lower montane coniferous forest, mesic, shady areas; mouth of Moss Creek Scrophulariaceae Mimulus laciniatus 4 SSP 900 2000 Chaparral, lower and upper montane coniferous forest, mesic areas of granitic substrate, vernally moist seepage areas; Yosemite Valley Scrophulariaceae Mimulus pulchellus 1B SSP 600 2000 Lower montane coniferous forest, vernally mesic meadows; Yosemite Valley Scrophulariaceae Penstemon azureus ssp. SSP 300 700 Chaparral, Yellow Pine Forest, Sagebrush Scrub, Foothill Woodland;occurrs under dry con- angustissimus ditions in slope habitats. Yosemite Valley. Scrophulariaceae Penstemon heterophyllus SSP 50 1600 Chaparral, Foothill Woodland, Yellow Pine Forest; occurs under dry conditions in slope var. purdyi habitats. Yosemite Valley Staphyleaceae Staphylea bolanderi SSP 300 1400 Chaparral, Foothill Woodland, Yellow Pine Forest; occurs in shaded canyon habitats; Mer- ced River Canyon in El Portal Typhaceae Sparganium natans 4 SSP 2000 2500 Freshwater wetlands, in lake-margin and edge habitats, tanks in meadows; tributaries of Merced River

48 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Appendix 3

Yosemite Special Status Plants Documented in Merced River Corridor

49 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

Appendix 4

Plant List for Wawona Golf Course

Family Scientific Name Common Name Life Form Native? Apiaceae Anthriscus caucalis bur-chervil Annual herb Non-native Apiaceae Heracleum lanatum cow parsnip Perennial herb Native Apiaceae Osmorhiza chilensis mountain sweet-cicely Perennial herb Native Apiaceae Sanicula crassicaulis Pacific sanicle Perennial herb Native Apiaceae Torilis nodosa knotted hedge-parsley Annual herb Non-native Aristolochiaceae Asarum hartwegii Hartweg’s wild-ginger Perennial herb Native Asteraceae Adenocaulon bicolor American trailplant Perennial herb Native Asteraceae Antennaria argentea silvery everlasting Perennial herb Native Asteraceae Artemisia douglasiana mugwort Perennial herb Native Asteraceae Bellis perennis English daisy Perennial herb Non-native Asteraceae Chrysothamnus nauseosus ssp. albicaulis white-stemmed common rabbitbrush Shrub Native Asteraceae Cirsium andersonii Anderson’s thistle Perennial herb Native Asteraceae Cirsium vulgare bull thistle Perennial herb Non-native Asteraceae Crepis capillaris smooth hawksbeard Perennial herb Non-native Asteraceae Hieracium albiflorum white hawkweed Perennial herb Native Asteraceae Hypochaeris glabra smooth cat’s ear Annual herb Non-native Asteraceae Lactuca serriola prickly lettuce Annual herb Non-native Asteraceae Senecio triangularis arrowhead butterweed Perennial herb Native Asteraceae Solidago canadensis ssp. elongata Canada goldenrod Perennial herb Native Asteraceae Solidago sp. unknown goldenrod Perennial herb Non-native Asteraceae Sonchus asper ssp. asper prickly sow thistle Annual herb Non-native Asteraceae Taraxacum officinale common dandelion Perennial herb Non-native Asteraceae Tragopogon dubius yellow salsify Perennial herb Non-native Asteraceae Wyethia angustifolia narrow-leaved mule-ears Perennial herb Native Asteraceae Wyethia helenioides whitehead wyethia Perennial herb Native Betulaceae Alnus rhombifolia white alder Tree Native Boraginaceae Myosotis micrantha small-flowered forget-me-not Annual herb Non-native Boraginaceae Plagiobothrys torreyi var. torreyi Torrey’s popcorn flower Annual herb Native Brassicaceae Capsella bursa-pastoris shepherd’s purse Annual herb Non-native Brassicaceae Rorippa nasturtium-aquaticum water cress Perennial herb (aquatic) Native Campanulaceae Heterocodon rariflorum few-flowered heterocodon Annual herb Native Caprifoliaceae Sambucus mexicana blue elderberry Tree, Shrub Native Caryophyllaceae Cerastium arvense field chickweed Perennial herb Native Caryophyllaceae Cerastium glomeratum mouse-ear chickweed Annual herb Non-native Caryophyllaceae Herniaria hirsuta ssp. cinerea grey herniaria Annual herb Non-native Caryophyllaceae Stellaria longipes var. longipes meadow starwort Perennial herb Native

50 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Appendix 4

Appendix 4

51 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

Plant List for Wawona Golf Course

Family Scientific Name Common Name Life Form Native? Chenopodiaceae Chenopodium album white goosefoot Annual herb Non-native Cornaceae Cornus sericea ssp. sericea red osier dogwood Shrub Native Cupressaceae Calocedrus decurrens incense cedar Tree Native Cyperaceae Carex amplifolia big-leaf sedge Perennial herb Native Cyperaceae Carex bolanderi Bolander’s sedge Perennial herb Native Cyperaceae Carex mariposana Mariposa sedge Perennial herb Native Cyperaceae Carex nudata torrent sedge Perennial herb Native Cyperaceae Carex senta swamp sedge Perennial herb Native Dennstaedtiaceae Pteridium aquilinum var. pubescens bracken Perennial herb Native Dryopteridaceae Athyrium filix-feminavar. cyclosorum subarctic lady-fern Perennial herb Native Dryopteridaceae Cystopteris fragilis brittle bladder fern Perennial herb Native Equisetaceae Equisetum arvense field horsetail Perennial herb Native Ericaceae Arctostaphylos viscida ssp. mariposa Mariposa manzanita Tree, Shrub Native Fabaceae Lathyrus latifolius perennial sweet pea Perennial herb Non-native Fabaceae Lathyrus nevadensis var. nevadensis Sierra Nevada pea Perennial herb Native Fabaceae Lathyrus sulphureus Brewer’s pea Perennial herb Native Fabaceae Lotus purshianus var. purshianus Spanish clover Annual herb Native Fabaceae Lupinus bicolor miniature lupine Annual herb Native Fabaceae Lupinus latifolius broad-leaf lupine Perennial herb Native Fabaceae Lupinus polyphyllus meadow-lupine Perennial herb Native Fabaceae Trifolium breweri Brewer’s clover Perennial herb Native Fabaceae Trifolium dubium shamrock Annual herb Non-native Fabaceae Trifolium pratense red clover Perennial herb Non-native Fabaceae Trifolium wormskioldii cows clover Perennial herb Native Fabaceae Vicia americana var. americana American vetch Perennial herb Native Geraniaceae Erodium cicutarium red-stemmed filaree Annual herb Non-native Grossulariaceae Ribes roezlii var. roezlii Sierra gooseberry Shrub Native Hydrophyllaceae Nemophila menziesii baby blue eyes Annual herb Native Hydrophyllaceae Nemophila parvifloravar. parviflora small-flowered nemophila Annual herb Native Hypericaceae Hypericum formosum var. scouleri Scouler’s St. Johnswort Perennial herb Native Iridaceae Iris missouriensis western blue flag Perennial herb Native Juncaceae Juncus bufonius toad rush Annual herb Native Juncaceae Juncus effususvar. exiguus common bog rush Perennial herb Native Juncaceae Luzula comosa hairy wood rush Perennial herb Native Lamiaceae Mentha spicata var. spicata spearmint Perennial herb Non-native Lamiaceae Nepeta cataria catnip Perennial herb Non-native Lamiaceae Stachys albens cobwebby hedge-nettle Perennial herb Native Liliaceae Chlorogalum pomeridianum var. common soaproot Perennial herb Native pomeridianum

52 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Appendix 4

53 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

Plant List for Wawona Golf Course

Family Scientific Name Common Name Life Form Native? Liliaceae Dichelostemma multiflorum wild hyacinth Perennial herb Native Liliaceae Smilacina racemosa large false-solomon’s-seal Perennial herb Native Liliaceae Trillium angustipetalum narrow-petaled wakerobin Perennial herb Native Liliaceae Triteleia ixioides pretty face Perennial herb Native Liliaceae Veratrum californicum var. californicum California corn lily Perennial herb Native Malvaceae Sidalcea glaucescens waxy checkermallow Perennial herb Native Onagraceae Circaea alpina ssp. pacifica Pacific enchanter’s nightshade Perennial herb Native Onagraceae Epilobium glaberrimum ssp. glaberrimum smooth willowherb Perennial herb Native Orchidaceae Goodyera oblongifolia rattlesnake plantain Perennial herb Native Oxalidaceae Oxalis albicans ssp. pilosa radish-root woodsorrel Perennial herb Native Pinaceae Pinus ponderosa ponderosa pine Tree Native Plantaginaceae Plantago lanceolata English plantain Perennial herb Non-native Poaceae Achnatherum lemmonii Lemmon’s needlegrass Perennial herb Native Poaceae Aira caryophyllea silver hairgrass Annual herb Non-native Poaceae Bromus diandrus ripgut brome Annual herb Non-native Poaceae Bromus tectorum cheatgrass Annual herb Non-native Poaceae Calamagrostis canadensis Canada reedgrass Perennial herb Native Poaceae Cynodon dactylon bermuda grass Perennial herb Non-native Poaceae Dactylis glomerata orchard-grass Perennial herb Non-native Poaceae Elymus glaucus blue wildrye Perennial herb Native Poaceae Festuca occidentalis western fescue Perennial herb Native Poaceae Festuca rubra red fescue Perennial herb Native Poaceae Glyceria elata tall mannagrass Perennial herb Native Poaceae Lolium perenne English rye-grass Perennial herb Non-native Poaceae Poa annua annual blue grass Annual herb Non-native Poaceae Poa pratensis Kentucky blue grass Perennial herb Non-native Poaceae Poa palustris fowl blue grass Perennial herb Non-native Poaceae Vulpia myuros var. myuros rattail fescue Annual herb Non-native Polemoniaceae Linanthus ciliatus whisker-brush Annual herb Native Polemoniaceae Navarretia divaricata ssp. divaricata mountain navarretia Annual herb Native Polemoniaceae Phlox gracilis annual phlox Annual herb Native Polygonaceae Polygonum bistortoides western bistort Perennial herb Native Polygonaceae Rumex acetosella common sheep sorrel Perennial herb Non-native Polygonaceae Rumex crispus curly dock Perennial herb Non-native Ranunculaceae Actaea rubra red baneberry Perennial herb Native Ranunculaceae Aquilegia formosa western columbine Perennial herb Native Ranunculaceae Delphinium gypsophilum gypsum-loving larkspur Perennial herb Native Ranunculaceae Ranunculus occidentalis western buttercup Perennial herb Native Ranunculaceae Ranunculus orthorhynchus straight-beaked buttercup Perennial herb Native

54 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Appendix 4

55 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Special Status Plant Species in the Merced River Corridor

Plant List for Wawona Golf Course

Family Scientific Name Common Name Life Form Native? Rhamnaceae Ceanothus integerrimus var. integerrimus deer brush Shrub Native Rosaceae Fragaria virginiana mountain strawberry Perennial herb Native Rosaceae Geum macrophyllum large-leaf avens Perennial herb Native Rosaceae Horkelia tridentata ssp. tridentata three-toothed horkelia Perennial herb Native Rosaceae Malus sylvestris domestic apple Tree Non-native Rosaceae Potentilla glandulosa gland cinquefoil Perennial herb Native Rosaceae Prunus persica peach Tree Non-native Rosaceae Prunus virginiana black cherry Tree Native Rosaceae Rubus discolor Himalaya-berry Shrub Non-native Rosaceae Rubus laciniatus cut-leaved blackberry Shrub Non-native Rubiaceae Galium aparine common bedstraw Annual herb Native Rubiaceae Galium bolanderi Bolander’s bedstraw Perennial herb Native Rubiaceae Galium triflorum sweet-scented bedstraw Annual herb Native Rubiaceae Kelloggia galioides kelloggia Perennial herb Native Salicaceae Populus balsamifera ssp. trichocarpa black cottonwood Tree Native Salicaceae Salix lasiolepis arroyo willow Tree, Shrub Native Salicaceae Salix lucida ssp. lasiandra shining willow Tree Native Scrophulariaceae Digitalis purpurea purple foxglove Perennial herb Non-native Scrophulariaceae Mimulus bicolor yellow and white monkeyflower Annual herb Native Scrophulariaceae Mimulus guttatus common yellow monkeyflower Perennial herb Native Scrophulariaceae Mimulus torreyi Torrey’s monkeyflower Annual herb Native Scrophulariaceae Veronica americana American speedwell Perennial herb Native Scrophulariaceae Veronica arvensis corn speedwell Annual herb Non-native Taxodiaceae Sequoiadendron giganteum giant sequoia Tree Native Violaceae Viola glabella pioneer violet Perennial herb Native Violaceae Viola purpurea ssp. quercetorum goosefoot yellow violet Perennial herb Native

56 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park. Appendix 4

57 Contains sensitive information: Copying or distributing is prohibited without written agreement from the Division Chief of Resources Management and Science, Yosemite National Park.

National Park Service U.S. Department of the Interior

EXPERIENCE YOUR AMERICA™