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Home , Indio Hills Palms, Orocopia Mountains, Xylorhiza, Xylorhiza cognata, Xylorhiza orcuttii, Xylorhiza tortifolia

RANCHO SANTA ANA BOTANIC GARDEN OCCASIONAL PUBLICATIONS

NUMBER 8

A CONSERVATION PLAN FOR MECCA ASTER, COGNATA ()

MITCHELL E. MCGLAUGHLIN

Published by Rancho Santa Ana Botanic Garden, 1500 North College Avenue, Claremont, 91711 2008

RANCHO SANTA ANA BOTANIC GARDEN OCCASIONAL PUBLICATIONS

NUMBER 8

A CONSERVATION PLAN FOR MECCA ASTER, (ASTERACEAE)

MITCHELL E. MCGLAUGHLIN

RANCHO SANTA ANA BOTANIC GARDEN OCCASIONAL PUBLICATIONS

RANCHO SANTA ANA BOTANIC GARDEN OCCASIONAL PUBLICATIONS (ISSN 1094- 1398) are published at irregular intervals in volumes of various sizes. This series of publications is designed to include results of original botanical research by members of the Rancho Santa Ana Botanic Garden staff, or by botanists who have collaborated in a Garden program. Proceedings of symposia sponsored by the Garden may also be published in this series.

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PUBLICATION DATA

A Conservation Plan for Mecca Aster, Xylorhiza cognata (Asteraceae). July 2008. Mitchell E. McGlaughlin. Vanessa Ashworth, Editor-In-Chief, Elizabeth Friar, Series Editor, and Lucinda McDade, Managing Editor. RANCHO SANTA ANA BOTANIC GARDEN OCCASIONAL PUBLICATIONS, Number 8, vi + 14 pages. ISSN 1094-1398. First printing: 50 copies, July 2008. Copyright © 2008, by Rancho Santa Ana Botanic Garden.

TABLE OF CONTENTS

List of Figures and Tables ...... vi

1.0 EXECUTIVE SUMMARY ...... 1

2.0 SCOPE AND PURPOSE ...... 1

3.0 BACKGROUND ...... 1 3.1 Species Description ...... 1 3.2 ...... 2 3.3 Biology and Ecology ...... 3 3.4 Habitat...... 3 3.5 Distribution and Abundance ...... 6 3.6 Population Trends...... 8 3.7 Threats and Limiting Factors ...... 8 3.8 Conservation Status...... 9

4.0 CONSERVATION...... 10 4.1 Conservation Objectives and Criteria...... 10 4.2 General Conservation Actions Recommended ...... 10 4.3 Site-Specific Actions ...... 11 4.4 Conservation Tasks ...... 11 4.5 Out-of-State Considerations...... 12 4.6 List of Likely Participants...... 12

5.0 IMPLEMENTATION...... 12 5.1 Action Assessment ...... 12 5.2 State and/or Federal Listing...... 12 5.3 Other Actions ...... 12 5.4 Potential Difficulties in Implementation ...... 13

ACKNOWLEDGMENTS ...... 13

LITERATURE CITED ...... 13 vi

LIST OF FIGURES Figure 1. Distribution map for Xylorhiza cognata...... 4 Figure 2. of Xylorhiza cognata ...... 4 Figure 3. Illustration of the inflorescence of Xylorhiza cognata...... 4 Figure 4. Xylorhiza cognata growing on a rocky slope ...... 5 Figure 5. Growth habit of Xylorhiza cognata in alluvial substrate...... 5 Figure 6. Habitat of Xylorhiza cognata...... 5

LIST OF TABLES Table 1. Summary of occurrence locations, abundance, and potential threats...... 7 Occasional Publications 8, pp. 1–13 A Conservation Plan for Mecca Aster, Xylorhiza cognata (Asteraceae) by Mitchell E. McGlaughlin © 2008, Rancho Santa Ana Botanic Garden that will preclude the need for State or 1.0 EXECUTIVE SUMMARY Federal listing. Xylorhiza cognata was selected for a conservation plan due to Xylorhiza cognata (H.M.Hall) the limited amount of biological T.J.Watson (Asteraceae, Mecca aster) is information available. The purpose of a native known from the Indio this plan is to compile all available Hills and of Riverside information about X. cognata, both from County, California (Fig. 1). The Cal- previous references and materials, and ifornia Native Society (CNPS) has from observations and data developed placed X. cognata on its 1B.2 list, for this review, in a single document classifying it as “fairly endangered” in useful for land managers, conservation California. Xylorhiza cognata is a organizations, State and Federal covered species in the agencies, and other interested parties. Multiple Species Habitat Conservation This document synthesizes all available Plan (CVMSHCP 2007) and will be data and sets forth immediate included in the Northern and Eastern conservation activities that are warranted Desert Coordinated Manage- and identifies areas where more ment Plan (NECO 2002) when it is information will be required to ensure completed. There are fewer than twenty the survival of this species. known extant occurrences of X. cognata. Xylorhiza cognata is not listed as 3.0 BACKGROUND threatened or endangered under the State or Federal Endangered Species Acts, and 3.1 Species Description no listing seems warranted at this time. Recommended management actions for Xylorhiza cognata is a woody shrub X. cognata include surveying for standing up to 1.5 m tall with distinctive additional occurrences, determining if white bark (Fig. 2–5). It branches from a of this species are associated with thick woody tap root, with main stems to a specific substrate, annual monitoring 1 cm in diameter and upper branches to of several occurrences to document 4 mm in diameter. Young stems and fluctuations in population size, branches are moderately to densely restricting off-highway vehicle (OHV) covered with short glandular trichomes, use in areas covered under the but become glabrous with age. Leaves CVMSHCP, and studying aspects of the are oblanceolate to ovate (1–5 cm long, species’ reproductive biology, phen- 0.3–2 cm wide) and are glabrous to ology, and life history to better moderately glandular. The apex of the determine appropriate conservation leaves is obtuse or acute and the leaf activities. base is slightly clasping around the stem. Leaves have a white mid-rib, are toothed 2.0 SCOPE AND PURPOSE or entire, and are not reduced toward apical portions of the plant as occurs in This conservation plan surveys all of some other members of the genus the known occurrences of this species, (Watson 1977). describes the threats to those occur- The inflorescence is composed of rences, if known, and outlines current as solitary radiate heads 2–4 cm wide (not well as potential conservation actions including the ray flowers), each on a 2 McGlaughlin OCCASIONAL PUBLICATIONS 0–11 cm long (Fig. 2–3). The 3.2 Taxonomy involucre is bell shaped or hemispheric, with phyllaries graduated in 4–7 series. Xylorhiza cognata is a member of The outer phyllaries are linear- Asteraceae, the sunflower family. Eight lanceolate, 8–19 mm long, 0.8–2.2 mm species of Xylorhiza are recognized, wide, and subglabrous to densely divided into two sections. All members glandular. The innermost phyllaries are of the genus are found in xeric regions of shorter than the outer. There are 20–30 the western United States and Mexico. ray flowers per head each with 5–8 mm The genus Xylorhiza was established in long corolla tubes and 1.8–2.5 cm long 1840 by Thomas Nuttall, who described oblong to elliptic ligules that are two species, X. glabriuscula, the type generally light blue. There are 40–80 species for the genus, and X. villosa disk flowers per head, 7–9 mm in length, (Nuttall 1840). Torrey and Gray (1842) with yellow corollas. The style branches transferred both species of Xylorhiza to are linear, 1.8–2.8 mm long, with acute genus Aster. Later, Greene (1896) appendages, 0.8–1.6 mm long. The fruit resurrected genus Xylorhiza to include is an achene that is linear to club-shaped, seven species. In a latter revision, 3–4.5 mm long, and woolly with long, Cronquist and Keck (1957) reduced silky, appressed hairs. Achenes are Xylorhiza to sectional status in genus topped with a pappus of 60–110 stout, . The most recent unequal bristles up to 9.5 mm in length treatment of the genus was done by (Watson 1977). Watson (1977), who returned to the Two other closely related species of generic circumscription of Greene Xylorhiza occur in southeastern (1896), including the eight species and California, but all three species have two sections recognized today. This is allopatric distributions. Xylorhiza torti- the currently accepted placement of X. folia generally occurs to the north and cognata (Nesom 2006). east of X. cognata, extending from the Recent molecular phylogenetic to the Chocolate examination of relationships among Mountains in California, and in , species recognized as Machaeranthera , and (Nesom 2006). by Cronquist and Keck (1957) and close is distinguished by relatives, have shown Xylorhiza as being a sub-shrub or herbaceous having a sister relationship to the core perennial, with narrow leaves that are Machaeranthera group (Morgan and reduced upwards, and 8–20 cm long Simpson 1992; Morgan 1997). However, peduncles. generally the molecular phylogenetic research only occurs south of the range of X. cognata included a single representative of in Imperial, Riverside, and San Diego Xylorhiza, X. wrightii, a species from Counties, and in Baja California, Mexico and adjacent Chihuahua, Mexico. (Nesom 2006). Xylorhiza orcuttii is Xylorhiza cognata was first des- distinguished by being a low growing cribed as Aster cognatus in 1915 by H. sub-shrub, that lacks glandular M. Hall (1915), based on his collection pubescence, and by the presence of from the “northerly side” of the broad phyllaries, the inner of which are Coachella Valley and specimens from larger than the outer. Red Canyon and Shavers’s Well on the east and west ends, respectively, of the NUMBER 8 Xylorhiza cognata 3

Orocopia Mountains. In 1923, Davidson resulted in a germination rate of less described Aster standleyi based on a than one percent (Watson 1977). Watson collection by Francis Fultz from Painted (1977) also noted that populations were Canyon in the Mecca Hills (Davidson composed predominantly of larger 1923a). In the same year Davidson plants, with limited evidence of seed- (1923b) transferred his species to lings or younger plants. Both Watson’s Xylorhiza as X. standleyi. Today this is laboratory seed germination experiments regarded as a synonym of X. cognata. and his lack of evidence of seedlings in Cronquist and Keck (1957) revised the field may indicate that recruitment is Machaeranthera, and the combination limited (Watson 1977). However, among M. cognata was made. Watson’s (1977) populations visited for this study, seed- resurrection of Xylorhiza yielded X. lings and younger plants were observed cognata (H.M.Hall) T.J.Watson, as in all populations that had more than 50 known today. individuals (Mitchell McGlaughlin pers. obs.). Currently, there is no information 3.3 Biology and Ecology about seed dormancy, required con- ditions for seed germination, or seedling Very little is known about the establishment rates. Until more infor- biology of Xylorhiza cognata. Plants are mation about the demography of X. long-lived perennials that exhibit several cognata is available, it is not possible to adaptations to their arid environment. assess conclusively the long-term prog- Most notably, vegetative growth occurs nosis for populations of the species. primarily in the spring when there is available moisture and cool temperatures 3.4 Habitat (Watson 1977). As temperatures increase and soil moisture decreases, Xylorhiza cognata is found in a growth subsides and some leaves abscise limited area of the northwestern (Watson 1977). Additional adaptations (Fig. 1). It occurs on to the arid environments include a thick, clays, rocky sands, gravel, gypsum soils, woody tap root, light-colored bark, and and alluvial substrates. Plants are glandular trichomes on the leaves and generally found growing in deep ravines stems. and on the exposed slopes above (Fig. Flowering occurs between January 6). Although some plants are found and June, with an apparent peak in April growing in sand and gravel in canyon and May. The means of pollination is bottoms, the majority of plants are unknown and the sunflower family generally found growing on adjacent contains a diverse array of pollination steep slopes. Plants occur at elevations syndromes and breeding systems. The of 20–240 m (65–790 ft), most upper portions of the fruits are covered frequently on west, southwest, and in a pappus of thick bristles, which may northwest facing slopes. aid in animal mediated dispersal. Stewart (1992) has suggested that X. Very little is known about the life cognata is associated with the Palm history or demography of this species. Springs and Canebrake geologic form- Seed-set seems to be high in the field ations, which are non-marine layers that (Watson 1977), but attempts by Watson originated during the Plio-Pleistocene to germinate seeds in the laboratory 4 McGlaughlin OCCASIONAL PUBLICATIONS NUMBER 8 Xylorhiza cognata 5 6 McGlaughlin OCCASIONAL PUBLICATIONS

era 0.75–1.8 million years ago (Norris disputed occurrences of Xylorhiza and Webb 1990). These geologic form- cognata are limited to two main areas in ations are primarily composed of con- Riverside County, the and glomerate, sandstone, and siltstone, with Mecca Hills, with several occurrences in localized patches of gypsum. These two each area (Fig. 1). The California related formations occur throughout the Natural Diversity Database (CNDDB western portions of the Colorado Desert 2007) recognizes 18 element occur- and are common in the Indio Hills and rences (EO; see Table 1). One specimen Mecca Hills (Norris and Webb 1990). was collected outside the Indio Hills and Despite the suggested affinity for these Mecca Hills, along the Palms to Pines formations, no detailed analysis of the Highway, by McMinn in 1935 (EO 19); substrate at specific X. cognata occur- this area has been converted to housing rences has been conducted. Additionally, and no remaining appropriate habitat the formations are more widely was seen in the area when the author distributed than are the known or visited it in 2005. historical populations of X. cognata. Little is known about the historical Xylorhiza cognata is found in abundance of Xylorhiza cognata. Most various Larrea tridentata (DC.) Cov. occurrences have only been surveyed (creosote bush) dominated communities. once in the last 30 years. Herbarium Other associated species include: Acacia specimens from the early to mid 1900s greggii A.Gray (catclaw acacia), exist for many general localities, but Ambrosia dumosa (A.Gray) Payne none of the collectors noted the (burrowbush), Atriplex canescens abundance of the species. Due to the (Pursh) Nutt. (four-winged saltbush), A. vague locality information on older hymenelytra (Torr.) S.Watson (desert herbarium sheets, it is difficult to holly), A. polycarpa (Torr.) S.Watson determine if specimens were collected (cattle spinach), Bebbia juncea Greene from the same occurrences recognized (sweetbush), Cercidium floridum Benth. today. ex A.Gray (palo verde), Chilopsis Information about known population linearis (Cav.) Sweet (desert willow), occurrences is presented in Table 1 and Encelia farinosa A.Gray ex Torr. (brittle Fig. 1, which summarize data from the bush), Gilia latifolia S.Watson CNDDB. In addition, field surveys were (broadleaf gilia), Hymenoclea salsola conducted by the author during the A.Gray (cheesebush), Olneya tesota spring of 2005. The Mecca Hills were A.Gray (desert ironwood), Peuce- visited Apr 9–10, 2005, and the number phyllum schottii A.Gray (pygmy cedar), plants dispersed over 0.25 miles of Phacelia crenulata Torr. ex Watson var. canyon was counted for one occurrence ambigua (M.E.Jones) J.F.Macbr. in Painted Canyon and five occurrences (purplestem phacelia), and Psoro- in Box Canyon along State Highway thamnus spinosus (A.Gray) Barneby 195. The Indio Hills were visited Apr (smoketree). 25, 2005, and the total number of plants at two occurrences, Malcomber Palms 3.5 Distribution and Abundance and Biskra Palms, was counted. Within the Indio Hills no plants are Xylorhiza cognata is endemic to known from west of Washington Street. Riverside County, California. Un- NUMBER 8 Xylorhiza cognata 7

Table 1. Summary of occurrence locations, abundance, and potential threats for Xylorhiza cognata. NA = data not available; these sites were not visited as part of the present study.

Location/Site CNDDB # plants observed # plants Potential threats Name Element (year)2 observed Occurrence during this (EO) study3 Number1 Indio Hills Malcomber 17 660 (1985) 300 OHV use Palms Biskra Palms 18 250 (1984) 170 OHV use Gravel Pit 16 7 (1984) NA gravel mining, OHV use Power Line 14, 15 200 (1984), 7 NA development, (1985) OHV use Mecca Hills Thermal 13 134 (1995) NA OHV use Canyon Painted Canyon 10, 12 25 (1976) 954 OHV use Box Canyon 3, 6, 7, 9 49 (1985), 520 15, 32, 83, road maintenance, (1985), 100-1000+ 116, 220 OHV use (1986) Hidden Springs 1, 4, 8 50-100 (1986), 10 NA OHV use Canyon (1986) Mortmar 2, 5 10 (1986), 50 NA OHV use (1986) Other Occurrences Palms to Pines5 19 0 extirpated 1 Element Occurrence number—corresponds to California Department of Fish and Game Natural Diversity Database element occurrence number (CNDDB 2007); occurrences within the same vicinity or canyon have been grouped. 2 # plants observed (year)—number of plants observed as recorded in the California Natural Diversity Database. 3 # of plants observed for this study—number of plants observed by the author in 2005. 4 Additional plants were seen in the area but detailed counts were not conducted. 5 Plants of this species are believed to be extirpated from this site.

Within the Mecca Hills plants are most plants, and the Mecca Hills area appears abundant in the small canyons to contain more than 5000 plants. originating from Box Canyon Road and Two occurrences of X. cognata from Painted Canyon Road. The Indio Hills Imperial County are listed in the area appears to contain a few thousand California Natural Diversity Database (CNDDB 2007), element occurrence 8 McGlaughlin OCCASIONAL PUBLICATIONS

numbers 11 and 20. However, specimens that reproduction and recruitment are upon which these occurrences were occurring. based have been redetermined. The author visited element occurrence 3.7 Threats and Limiting Factors number 11, located near Salton City, in 2005, and the plants at that site were The major threats to Xylorhiza determined to be X. orcuttii. The cognata relate to OHV use, its limited specimen that served as the basis for overall distribution, and the relative CNDDB element occurrence number 20, isolation among occurrences. Limited collected from the , knowledge of the basic biology of plants has been re-classified as X. tortifolia by of this species makes it difficult to the original collector (Sarah DeGroot identify and assess other possible threats. pers. comm.). Habitat degradation by OHV activity is the most immediate and significant 3.6 Population Trends source of threat. OHV activity impacts X. cognata by damaging established Table 1 makes clear that occurrences plants that occur in accessible areas and with relatively large populations of X. by disturbing soil, possibly preventing cognata have existed and continue to new plants from becoming established. exist in the Indio Hills and Mecca Hills. The Mecca Hills Wilderness Area Due to the scattered nature of the encompasses the majority of known occurrences and variable number of occurrences in the Mecca Hills and is plants present, it is probable that some closed to OHV use. However, evidence small or isolated occurrences have not of OHV activity was observed on the been located. We have limited margins of the Mecca Hills Wilderness, information about historical population but no direct damage to plants was sizes. However, the long history of observed (Mitchell McGlaughlin pers. collections made in Box Canyon along obs.). The second major area of State Highway 195, in relatively occurrences, the Indio Hills, faces disturbed sites, and the current large increasing pressure from urban and populations at those sites, suggest that commercial development and OHV no major changes in population activity as other local areas become abundance have occurred. Surveys closed to vehicles. Evidence of OHV use conducted for this study generally and damage to plants growing on documented fewer total plants than alluvial substrates was seen at both historical records from the mid 1980s, occurrences visited in Indio Hills (EO 17 but populations were not small. Due to and 18) during the course of this study vague locality data of previous (Mitchell McGlaughlin pers. obs.). collections and unknown census Due to the limited distribution of X. methods, the idea that populations of the cognata, cumulative habitat loss and species are declining must be viewed degradation could have long-term with caution. It is likely that population impacts on its survival. We do not know sizes will fluctuate over time. the minimum population size of an Additionally, seedlings and juvenile occurrence for it to remain viable or the plants were documented at all of the number of occurrences necessary in a populations visited in 2005, indicating region for the species to persist. Biotic NUMBER 8 Xylorhiza cognata 9

impacts, such as disease and inbreeding, 3.8 Conservation Status or abiotic impacts, such as drought, could severely reduce the distribution of The CNPS has placed X. cognata on X. cognata if multiple occurrences were its inventory of rare and endangered to be lost. Also, as urban development plants, designating this species as a expands, even occurrences at protected CNPS list 1B.2, which covers species sites are likely to experience more that are “fairly endangered” in impacts from non-native species and California. Such species meet the edge effects. definitions of Sec. 1901, Chapter 10 Most plant species exist as ass- (Native Plant Protection Act) or Secs. emblages of occurrences that exchange 2062 and 2067 (California Endangered seed and pollen, and independently Species Act) of the California Depart- fluctuate in size and position over time. ment of Fish and Game Code and are Some occurrences may be extirpated eligible for state listing (CNPS 2007). At while new ones are established and the present time there is no official historical occurrences repopulated, thus federal or state status for this taxon. constituting a meta-population. Due to Most populations of X. cognata the subdivided nature of preserved located in the Mecca Hills are contained habitat within the Indio Hills and the within the federally designated Mecca distance between the Mecca and Indio Hills Wilderness, which is managed by Hills, gene exchange among populations the Palm Springs Field Office of the and re-colonization of previously Bureau of Land Management (BLM). inhabited areas may not be occurring. The Mecca Hills Wilderness is closed to The lack of historical collections from all OHV use. the area between the Mecca and Indio Xylorhiza cognata is also a covered Hills suggests that these areas have species in the Coachella Valley Multiple always been isolated. Species Habitat Conservation Plan The lack of information about the (CVMSHCP 2007), which is expected to basic biology of X. cognata makes be finalized in 2008. Xylorhiza cognata additional threats difficult to identify and has been included as a covered species evaluate. For instance, if this species in the draft Northern and Eastern relies on a specific pollinator that goes Colorado Desert Coordinated Manage- extinct then it will stop producing viable ment Plan (NECO 2002). Conservation seed and occurrences will gradually go goals within the CVMSHCP that relate extinct. The aspects of its biology that to X. cognata include: pose the greatest potential threat if 1. Protect core habitat that includes disrupted relate to its reproductive occupied habitat in the following output, conditions required for seeds to conservation areas: Thousand Palms germinate, and conditions required for Conservation Area, plants to grow at a given site. Know- Conservation Area, East Indio Hills ledge of the basic biology of this species Conservation Area, Desert Tortoise would be advanced by field studies and Linkage Conservation Area, and designed to document these aspects of Mecca Hills/ plant biology. Conservation Area. 2. Protect other conserved habitat to provide for natural communities, 10 McGlaughlin OCCASIONAL PUBLICATIONS

essential ecological processes, 4.2 General Conservation Actions biological corridors and linkages, Recommended population fluctuations and genetic diversity in the following conservation Xylorhiza cognata appears to be areas: Edom Hill Conservation Area regionally rare and locally abundant. and Indio Hills/Joshua Tree National Conservation actions should focus on the Park Linkage Conservation Area. identification and preservation of 3. Ensure conservation of habitat quality habitat. This goal is best accomplished through biological monitoring and by supporting the activities of the management actions to ensure self- CVMSHCP to secure and manage sustaining populations within each additional acreage of habitat in the core habitat. region. It is also important that OHV 4.0 CONSERVATION restrictions in Conservation Areas and the Mecca Hills Wilderness are 4.1 Conservation Objectives and enforced. Many occurrences of X. Criteria cognata are effectively protected from human impacts because plants are Conservation objectives for X. growing on steep, inaccessible slopes. cognata developed here are as follows. However, it is important that OHV travel 1. Determine the location, condition, and in washes is not allowed within extent of population occurrences. occurrences and that care is taken with 2. Determine if plants of this species are the construction of trails or other associated with the Palm Springs and improvements in conserved areas. Canebrake formations and, depending The limited distribution of X. upon the degree of specificity, survey cognata increases the importance of these formations for additional protecting all known occurrences. Due to occurrences. its limited distribution, surveys in a 3. Protect as much habitat as possible in limited area could lead to a good the Indio Hills and Mecca Hills and understanding of the distribution and limit human impacts at all known extent of X. cognata occurrences. occurrences. The two largest known X. cognata 4. Conduct research on basic biology of occurrences in the Indio Hills, X. cognata to better understand Malcomber Palms and Biskra Palms, are population trends and potential threats. located on land owned by the California Specific research topics include Department of Parks and Recreation, and studies of: will be incorporated into the Indio Hills a) Breeding system Palms Conservation Area when the b) Seed dispersal and predation CVMSHCP is completed. However, c) Seedling requirements and these areas are currently not effectively survival closed to OHV use. In the Mecca Hills d)Distribution of genetic the majority of habitat is protected diversity within the Mecca Hills Wilderness, but e) Impact of invasive non-native there is adjacent habitat to the west that plants also warrants consideration for conservation. NUMBER 8 Xylorhiza cognata 11

Little is known about the basic 4.4.1 Population locations and biology of X. cognata. Conservation extent.—This species has been suggested activities would be enhanced by research to be associated with the Palm Springs to determine pollinators, breeding and Canebrake formations. If research system, habitat and seed germination confirms that these geologic associations requirements, dispersal mechanisms, are consistent, additional sites within the frequency and scope of population fluc- Indio Hills and Mecca Hills where these tuations, and population demography. geologic formations occur should be surveyed, as well as areas outside these 4.3 Site-Specific Actions two regions where these formations occur. Plants have been documented Indio Hills (EO numbers 14–17; Table 1, from the most accessible sites within the Fig. 1).—Xylorhiza cognata occurrences Indio Hills and Mecca Hills but it is not in the Indio Hills are primarily known whether the less accessible areas associated with exposed slopes that have of these regions might harbor pop- been suggested to be part of the Palm ulations of this species. Springs and Canebrake formations. This substrate is not abundant in the area, so 4.4.2 Habitat conservation.—At the it is important that locations where there present time, most of the Indio Hills are is similar substrate are protected. OHV protected via a patchwork of conser- activity is common in the area and vation plots managed by various should be limited. Expansion of gravel agencies. The activities of the mining in the southeast section of the CVMSHCP serve to unite the many Indio Hills could also remove available landowners in the Indio Hills and apply habitat if new pits are established. unified conservation standards. These efforts should be supported as well as Mecca Hills (EO numbers 1–10, 12–13; the acquisition of additional areas of Table 1, Fig. 1).—The largest known suitable habitat. Furthermore, adequate occurrences in the Mecca Hills do not OHV barriers should be installed in all require any additional immediate impacted areas. conservation actions due to their in- clusion within the Mecca Hills Wild- 4.4.3 Basic biological studies.— erness area. It is important that existing Conservation activities could be restrictions on OHV use continue to be informed by research to determine enforced and that any recreation trails pollinators, breeding system, habitat and constructed avoid disturbing known seed germination requirements, dispersal occurrences. mechanisms, frequency and magnitude of population fluctuations, and demo- 4.4 Conservation Tasks graphy. At present, X. cognata appears to have very limited seed production, The major conservation tasks fall with few filled seeds (Mitchell into three categories: determination of McGlaughlin pers. obs.). Limited seed population location and extent, habitat production could be related to pollinator conservation in the Indio Hills, and basic limitation, seed predation, or resource biological studies. availability, or might be associated with breeding system, particularly self- 12 McGlaughlin OCCASIONAL PUBLICATIONS

incompatibility. Additionally, specific in the CVMSHCP, and limiting OHV occurrences within the Indio Hills and use in the area. Mecca Hills should be identified for regular population censuses. This would 5.2 State and/or Federal Listing allow land managers to better understand fluctuations in population size and to Xylorhiza cognata does not appear to react to population declines that are warrant state or federal listing at this outside the normal range. time. None of the large occurrences documented in 1985–86 have been 4.5 Out-of-State Considerations extirpated. Nine of the 12 element occurrences in the Mecca Hills are Xylorhiza cognata is endemic to contained within the Mecca Hills Riverside County, California. Therefore, Wilderness. Within the Indio Hills, the there are no out-of-state or international two largest element occurrences will be considerations. protected under the CVMSHCP. Future documented decreases in population size 4.6 List of Likely Participants or distribution, or documented increases in threats could signal that listing is • Coachella Multiple Species warranted. Habitat Conservation Plan • California Department of Fish 5.3 Other Actions and Game • California Department of Parks Currently, there are no species- and Recreation specific management activities in place • Bureau of Land Manage- for X. cognata. If funding is available ment—Palm Springs Office the following management prescriptions • Northern and Eastern Colorado are recommended. Desert Coordinate Management 1. Continue surveys for X. cognata in Plan participants areas within the CVMSHCP area, the • Rancho Santa Ana Botanic Mecca Hills, and locations where the Garden Palm Springs and Canebrake • Riverside County formations occur. • California Native Plants Society 2. Annual or bi-annual population censuses of multiple occurrences 5.0 IMPLEMENTATION within the Mecca Hills and Indio Hills with particular attention to recruitment 5.1 Action Assessment of new individuals. 3. Application of unified conservation Xylorhiza cognata is regionally rare, standards in the CVMSHCP area, but has large occurrences in both the including an enforced closure to Indio Hills and Mecca Hills. The OHVs. conservation tasks listed above generally 4. Basic biological studies to determine related to gaining a better understanding pollinators, breeding system, habitat of the species’ biology, determining and seed germination requirements, additional occurrences, supporting the dispersal mechanisms, frequency and ongoing conservation activities outlined NUMBER 8 Xylorhiza cognata 13

scope of population fluctuations, and Machaeranthera. Brittonia 9: population demography. 231–239. DAVIDSON, A. 1923a. New plants from 5.4 Potential Difficulties in Implemen- S. California. Bulletin of the tation Southern California Academy of Sciences 22: 5–6. Inadequate funds may be a major . 1923b. Xylorhiza, pp. 386–387. impediment to implementation of the In A. Davidson and G. L. Mocley recommendations presented here. [eds.], Flora of Southern California Furthermore, the CVMSHCP may not be pp. 387. Los Angeles Times—Mirror fully implemented with respect to the Press, California, USA. needed conservation actions for X. GREENE, E. L. 1896. Studies in the cognata due to political or financial Compositae. III. Pittonia 3: 43–63. reasons. HALL, H. M. 1915. New and noteworthy Californian plants. Univ. Calif. Publ. ACKNOWLEDGMENTS Bot. 6: 173–174. MORGAN, D. R. 1997. Reticulate Special thanks to Elizabeth Friar and evolution in Machaeranthera Gary Wallace who initiated the writing (Asteraceae). Syst. Bot. 22: 599–615. of conservation plans for rare species of AND B. B. SIMPSON. 1992. A California as a course at Rancho Santa systematic study of Machaeranthera Ana Botanic Garden. Scott White, (Asteraceae) and related groups Naomi Fraga, and Lucinda McDade using restriction site analysis of were very helpful in reviewing a draft of chloroplast DNA. Syst. Bot. 17: this document. 511–531. NESOM, G. L. 2006. Xylorhiza, p. 406. In LITERATURE CITED Flora of North America Editorial Committee [eds.]. 1993+. Flora of CALIFORNIA NATIVE PLANT SOCIETY North America North of Mexico, (CNPS). 2007. Inventory of rare and vol. 20. New York, USA. endangered plants. NORRIS, R. M. AND R. W. WEBB. 1990. http://www.cnps.org/inventory/ (Jan Geology of California. Jon Wiley & 2008) Sons, New York, USA. 157 p. CALIFORNIA NATURAL DIVERSITY NORTHERN AND EASTERN COLORADO DATABASE (CNDDB). 2007. Version DESERT COORDINATED 3.1.1. California Department of Fish MANAGEMENT PLAN, DRAFT and Game. (NECO). 2002. http://www.dfg.ca.gov/biogeodata/cn http://www.blm.gov/ca/st/en/fo/cdd/n ddb/ (30 Sep 2007). eco.html (Jan 2008) COACHELLA VALLEY MULTIPLE SPECIES NUTTALL, T. 1840. Descriptions of new HABITAT CONSERVATION PLAN species and genera in the natural (CVMSHCP). 2007. order Compositae, etc. Trans. http://www.cvmshcp.org/ (Jan 2008) American Philosophical Society II. CRONQUIST, A. AND D. D. KECK. 1957. 7: 297–298. A reconstruction of the genus 14 McGlaughlin OCCASIONAL PUBLICATIONS

STEWART, J. M. 1992. Colorado Desert America, vol. 2, Wiley and Putnam, wildflowers. Jon Mark Stewart, Palm New York, USA. Desert, California, USA. 120 p. WATSON, T. J. 1977. The taxonomy of TORREY, J. AND A. GRAY. 1842. Xylorhiza (Asteraceae—). Xylorhiza, pp. 158–159. In J. Torrey Brittonia 29: 199–216. and A. Gray [eds.]. Flora of North