Plant Associations. and Plant Species of Special Concern in the Jack Morro:W Hills Ecosystem

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Plant Associations. and Plant Species of Special Concern in the Jack Morro:w Hills Ecosystem

Prepared for the Bureau of Land Management Rock Springs District

By (_) George.Jon~s and Walter Fertig. Wyoming Natural Diversity Databas·~ ·1604. Grand Ave.. · Laramie, Wyoming 82070

February 29, 1.996.

- ·".! Agreement # K9lO-A4-0011 ·' Task Order # 6

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1 ' TABLE OF CONTENTS LIST OF TABLES ...... 2 LIST OF FIGURES • ...... 2

INTRODUCTION • • • • • • • • • • • • • • • • • • • • • a • • 4

~THODS • • • • • • • • • • • ~ • • • • • • • • • o· • 4 -PLANT COMMUNITIES • • • • • • • • • • • • ••• '4 PLANT SPECIES OF SPECIAL CONCERN • .• • • • • • • . • • • 8

RESULTS • . • • • • • 9

PLANT COMMUNITIES • • • • • • • • • • • • • • I 9 PLANT SPECIES OF SPECIAL CONCERN . . . • . • • '41 Antennaria arcuata • • • • • • • • • 46 Astragalus nelsonianus . • • • • • • ··49. Carex parryana • • • . • • • • • • • • • • 52 Cryptantha scoparia • • • • • • • • • • • • 55 Eriastrum wilcoxii . • • • . . . • . • . . $7 Erigeron uintahensis • • • • • • • • • • . 59 Eriogonum divaricatum • • • • • • • • • . • • . 62 Ipomopsis crebrifolia • • • • • • • • • . • • . 64 Lesauerella macrocarpa • • . . . . . o • o 66 Monolepis pusilla • • • • • • • • • . • . • • • 71 Oryzopsis contracta • o • • o • • o o o • o 73 oxytheca dendroidea • • • • • • • • • • • • • • • o 76 Penstemon paysoniorum • • • • • • • • • • • . • . • 78 Phacelia demissa • • • • • • • • • • • o • o • 80 Phacelia salina • • • • • • • • • • • . •. • . • • • 82 Phacelia scopulina . • • • • • • • • • . • • • • • 84

DISCUSSION AND MANAGEMENT RECOMMENDATIONS • • • • . • . • • • 86 PLANT COMMUNITIES • . . • • • • • • • • 86 PLANT SPECIES OF SPECIAL CONCERN • • • • • • • • • • 86

LITERATURE CITED 88 Appendix 1. Wyoming.Gap Analysis Project land cover map.for the Jack Morrow Hills Ecosystem. • • • • • • • • • • • . .92 Appendix 2. Life-form classes and canopy cover classes used

in the plant association tables. • • . . . o • • • • •.••.·:: ,_._-93 Appendix 3. 7.5 minute quadrangles (1:24,0000-scale topograph-ic maps) of the Jack Morrow Hills Ecosystem showing stands of mountain shrub vegetation. . o : o 94

... ~ i .. Appendix 4. Element occurrence records for the mounta~n shrub plant associations studied in the Jack Morrow Hills Ecosystem Project. • • • • • • • • • • • · 97

1 / · Appendix 5. Photographic slides of mountain shrub plant a~sociations in the Jack Morrow Hills Ecosystem. • •.• 127 Appendix 6. Names of plant species in vegetation plots sampled in the Jack Morrow Hills Ecosystem. • •• ' ••• 129 Appendix 7. Element Occurrence Records and Location Maps for Plant Species of Special Concern of the Jack Morrow Hills Ecosystem. • • • • • • • • •. • • • • • • • · • • • • 132

LIST OF TABLES Table 1. Locations, aspects, slopes, and elevations of · vegetation plots sampled in the ·Jack Morrow Hills Ecosystem project. • • • • • • • • • • • • • • • • • • • 13 Table 2a. Canopy cover of vascular plant species in plots of the mountain big sagebrush-Utah snowberryjbasin wildrye association. • • • • • • • • • • • • • • • • • • 17 Table 2b. Canopy cover of vascular plant species in the plot of the .mountain big sagebrush/bluebunch wheatgrass association. • • • • • • • • • • • • • • • • • • • • .22 Table 3. Canopy cover of vascular plant species in the basin wildrye plot. • • • • • • • • • • • • • • • • 24 Table 4a. Canopy cover of vascular plant species in the basin big sagebrush/basin wildrye plots. • • • • • • 25 Table 4b. Canopy cover of vascular plant species in plots of the basin big sagebrush/lemon scurfpea association. • 27 Tab+e 5. canopy cover of vascular plant species in the true mountain mahogany plots. • • • • • • • • • • • • • • 31 Table 6. Canopy cover of vascular plant species in the Utah juniper plots • • • • • • • • • • • • • • • ~ • 34 Table 7a. Canopy cover of vascular plant species in plots of the Wyoming big sagebrush/western wheatgrass association. • • • • • • • • • • • . • • • • • • • • .• • • 37 Table 7b. Canopy cover of vascular plant species in plots of the Wyoming big sagebrushjbluebunch wheatgrass association. • • • • • • • • • • • • • • • • • • • . • • 3 9 Table 8. Target Plant Species for Survey in the Jack Morrow Hills Ecosystem. • • .• • • • • • • • • • • • • • • • • • 44 Table 9. Plant Species of Special Concern of the Jack Morrow Hills Ecosystem. • • • • • • . . . • . . . . 45 Table 10. Lesquerella macrocarpa Transect # 3 Census Data. • 69 Table 11. Lesguerella macrocarpa Transect # 3 Census Data (From Fertig 1995 b) • · • • • • • • • . • • . • • • • • • .- 70

LIST OF FIGURES Figure 1. Map of Wyoming counties showing the approximate location of the Jack Morrow Hills Ecosystem Project study area...... 5

2 Figure 2. Map of the Jack Morrow Hiils· Ecosystem showing 4 the routes travelled and the locations of sampling points for the plant community work. 0 0 0 0 0 0 7

Figure 3. Antennaria arcuata. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 48

Figure 4. Astragalus nelsonianus. 0 0 0 0 0 0 .. 0 0 0 0 0 0 51 ... Figure 5. Carex 12ar;rxana var. 12ar;rxana. 0 0 0 0 0 0 0 0 54

Figure 6. CrvDtantha sco12aria. 0 0 0 0 0 0 0 0 0 0 0 56

Figure 7. Eriastrum wilcoxii. 0 0 0 0 0 .0 0 0 0 0 0 0 0 0 0 58

Figure 8. Erigeron uintahensis. 0 0 0 0 0 0 0 0 0 0 0 0 61 Figure 9. Eriogonum divariciatum. 0 0 0 0 0 0 0 0 0 0 0 • 63 Figure 10. IROmORSis cre};n::.ifol ia 0 0 0 0 0 0 0 0 0 0 0 0 65

Figure 11. Lesgyerella macrocama. 0 0 0 0 0 0 0 0 0 0 0 0 0 68

Figure 12. .Mono1e:12is 12usilla. 0 0 0 0 0 0 0 0 0 0 0 0 0 72

Figure 13. O;rxZORSis contracta. 0· 0 0 0 0 0 0 0 0 • 0 0 0 0 0 75

Figure 14. O~theca dendroidea. · 0 0 0 0 • 0 0 0 0 0 0 0 0 77

Figure 15. Penstemon 12a~soniorum. 0 0 0 0 0 0 0 0 0 0 0 79

Figure 16. Phacelia demissa. 0 0 0 0 0 0 0 0 0 0 . 0 0 0 0 0 0 81

Figure 17. Phacelia salina. 0 0 0 0 0 0 0 ·0 0 0 0 0 0 0 0 0 83

3 INTRODUCTION The Jack Morrow Hills Ecosystem encompasses nearly 700,000 acres of high elevation, cold desert in north-central Sweetwater and southwestern Fremont counties, Wyoming (Figure 1). The ecosystem contains a variety of unusual habitats of critical significance to native game animals and sensitive plant and animal species. It also contains a number of natural resources of value to commodity groups and recreationalists. In 1995 the Bureau of Land Management (BLM) Rock Springs District contracted on a cost-share basis with The Nature Conservancy's Wyoming Natural Diversity Database (WYNDD) to conduct surveys of plant communities and species of special management interest within the Jack Morrow Hills Ecosystem. The objectives of this project were to: (1) ground-truth the 1:100,000-scale maps of vegetation types for the Ecosystem provided by the Wyoming Gap Analysis Project (GAP), and produce 1:24,000-scale maps of stands of mountain shrubs (tall sagebrush, antelope bitterbrush, serviceberry, 9hokecherry, and snowberry) in the Ecosystem; (2) list the most common plant species and the diagnostic plant species in each type of mountain shrub vegetation; 3) collect biological information and map populations of US Fish and Wildlife Servic.e (USFWS) candidate, Rock Springs District special status, and WYNDD plant species of special concern within the study area; 4) identify areas of native vegetation suitable for special management designation, including areas that represent the vegetation types of the Ecosystem and areas with rare or unique vegetation types. The mountain shrub vegetation in the Steamboat Rim area (in the southern part of the Ecosystem) is relatively well known, so it was recognized early on that most of the work in this project should concentrate on finding and describing other areas of mountain shrub vegetation in the Ecosystem. METHODS PLANT COMMUNITIES The term "mountain shrub", as used in this project, means vegetation tall enough to serve as cover for elk and mule deer, or containing species that are especially important as food for elk and deer. Patches of vegetation thought to be mountain shrub stands were initially identified from 1:24,000-scale, true-color aerial photos and the 1:100,000-scale GAP cover type map and

4 Figure 1. Map of Wyoming counties showing the approximate location of the Jack Morrow Hills Ecosystem Project study area.

WYOMING

•') WESTON \~"'•; !i ~... ·

CONVERSE

GOSHEN

SWEETWATER

UINTA LARAMIE

0 25 50 MILES

5 drawn onto 1:100,000 and 1:24,000-scale topographic maps of the Ecosystem. These maps were used to select travel routes for extensive survey of the vegetation and stands for intensive sampling. The extensive surveY consisted of driving routes that allowed inspection of differ.ent types of shrub stands and that allowed a view of most of the Ecosystem (Figure 2). Notes were made about the distribution of vegetation types, their topographic position and substrates; the obvious species present in different vegetation types, and the overall aspect of the vegetation. Photographs were taken to illustrate vegetation patterns. Particular attention was paid during the extensive survey to mountain shrub stands. · Mountain shrub stands were selected for intensive sampling that represent the variation in species composition, vegetation structure, and topographic positions on which the stands grow. An attempt was made to distribute the sample stands throughout the Ecosystem. The following information was collected for each sample stand: topographic position; slope steepness and slope aspect (meqsured); type of substrate; si·ze of the stand (estimated) ; . elevation (recorded from topographic map); height (estimated) and patchiness of the vegetation; signs of geological, biological, and anthropogenic disturbance; adjoining vegetation types. One or more temporary plots, each covering several hundred square meters, were marked out in each .sample stand to represent · the variation in species composition or vegetation structure within the stand. The following information was collected in each plot: the amount of canopy cover (estimated by cover class) and the height (estimated) of each vascular plant species in each vegetation layer (Appendix 2); the amounts of rock, bare· soil, wood, and litter on the soil surface (estimated by cover class); the presence of erosional features or disturbances not observed in the rest of the stand; evidence of browsing on t.he shrubs and other signs of use by ungulates. The location of the plot within the stand and the part of the stand that the plot represented were also recorded, and a photograph was taken of the plot. Specimens of unknown plants were collected for later identification. -L 6 Figure 2. Map of the Jack Morrow Hills Ecosystem showing the routes travelled and the locations of sampling points for the plant community work. (The map is in the pocket following this page.)

Ecosystem Boundary

Extensive survey routes, plant community survey

Sites of intensive plant community sampling • 1St;J¢1 l

7 The sample stands similar in vegetation composition and structure were placed together into plant associations using, when possible, the vegetation classification developed for Wyoming by the Wyoming Natural Diversity Database (Jones 1992) and the classification developed by The Nature Conservancy for the western United states (Bourgeron and Engelking 1994). In most cases, classification of stands was base~ on the species ·contributing the most cover to the shrub layer and to the herbaceous layer in the plots within that stand. For example, stands with plots having a shrub layer composed mainly of mountain big sagebrush with a substantial amount of Utah snowberry, and a herbaceous layer with basin wildrye as the main species, were placed into the mountain big sagebrush-Utah snowberry/basin wildrye association. In .a few cases, a s·tand was placed into an association even though the plot from that stand contained little of the herbaceous species that dominated other stands in the association. For example, some of the plots from stands placed in the mountain big sagebrush-Utah snowberryjbasin wildrye association contained little basin wildrye but substantial amounts of the other herbaceous species (alkali bluegrass and Nelson's needlegrass) present in stands of that

association. \

The accuracy of the 1:100,000~scale GAP vegetation map was assessed during the extensive survey, and the initial 1:24,000- scale maps were adjusted, with some of the shrub stands mapped X4 from the aerial photos being erased and other stands not apparent on the aerial photos being added. The information from the extensive survey and the intensive sampling was used to assign each of the shrub stands on the maps to a plant association. PLANT SPECIES OF SPECIAL CONCERN Special status plant surveys were conducted in mid June and late July 1995. Prior to beginning fieldwork, information on the habitat needs and known distribution of target species was obtained from secondary sources, including WYNDD files and computer databases, collections of the Rocky Mountain Herbarium (RM), the literature, and knowledgeable individuals. USGS topographic maps, geologic maps, and BLM land status maps were used to identify areas· of potential habitat for ground surveys. ·In the field, data were collected on the biology; habitat, population size, and management needs of target species. Locations of plant populations were ~apped on 7.5' USGS topographic maps. When populations were sufficiently large voucher specimens were collected for deposit at the RM. Information gathered in the field was entered into the computerized Element Occurrence database of WYNDD.

8 RESULTS PLANT COMMUNITIES Three of the project's four objectives are relevant to plant communities, and the results of tl;le plant community work are presented for each of these objectives. Objective 1: A. Ground-truth the 1:100,000-scale vegetation map provided by the Wyoming Gap Analysis Project (GAP). The map provided by the Gap Analysis Project (Appendix 1) shows general vegetation units for the entire Ecosystem. Polygons were digitized from Landsat satellite images and then labeled based on the most common cover type present. Because the smallest area shown on this map is 250 acres (100 ha), only the most common vegetation type is shown for most of the area; small stands of secondary vegetation types are not shown. For most of the Ecosystem, the GAP map accurately shows the dominant cover type: a mosaic of sparse Wyoming big sagebrush/grass vegetation and Gardner saltbush vegetation, with grass-:dominated riparian vegetation along Jack Morrow creek. The field survey conducted for this project showed that the Wyoming big sagebrush vegetation and Gardner saltbush vegetation matrix contains patches of the following vegetation types: mountain big· sagebrush vegetation on slopes and esca~ments; cushion plant vegetation on rims; sparse Utah juniper woodland on steep, mainly south-facing slopes; sparse patches of true mountain mahogany shrubland on a few sandstone outcrops; and small groves of aspen and limber pine, mainly on north-.facing. and east-facing slopes. For the most part, these patches are smaller than 250 acres and so do not show up on the GAP map. · In two areas, the cover type mapped on the GAP map differs from the cover types observed in the extensive survey. The first ·is in the north-central part of the Ecosystem, where woodlands on Pacific Butte (on the Pacific Springs 7.5 minute quadrangle) and two unnamed buttes to the east (.on. the Dickie Springs quadrangle) are shown on the GAP map as limber pine woodland. Limber pine contributes substantial cover in those woodlands, but aspen appears to contribute at least as much cover (and probably more), and the woodlands would be better mapped as aspen, as they are on the vegetation map (Map E) of the draft Green River Resource Area resource management plan (USDI Bureau of Land Management 1992). The second area is southwest of Steamboat Rim and south of Essex Mountain in the southwestern part of the Ecosystem, on the North Table Mountain, Boars Tusk, Essex Mountain, and Ox Yoke Spring quads, where the vegetation of tall basin big sagebrush on

9 aeolian sand is shown on the GAP map as the Wyoming big sagebrush ( cover type. This tall basin big sagebrush differs markedly in species composition and vegetation structure from the Wyoming big sagebrush/grass vegetation in the rest of the Ecosystem, and the two could be mapped differently even at the scale and resolution of the GAP map. (The vegetation map, Map E, of the draft Green River Resource Area management plan [USDI Bureau of Land Management 1992] also fails to differentiate this unusual vegetation from other sagebrush areas in the Ecosystem.) The area of basin big sagebrush mapped on the 1:24,000-scale maps for this project is not indicated on the ·1:100,000-scale map because the boundary of that type on the 1:24,000-scale maps is an approximation taken from aerial photographs and field observation. If correction of the GAP map is deemed necessary, it should be accomplished by careful digitizing of the basin big sagebrush into a geographic information system vegetation from aerial photographs and field study to determine more accurately the boundaries of the type. The GAP cover type map for the Jack Morrow Hills Ecosystem is part of the cover type map of all of Wyoming, and given the enormous effort required to produce the statewide map, errors like the apparent misidentification of the area of basin big sagebrush in the Ecosystem are inevitable. Only portions of the draft version of the statewide GAP map have been checked for accuracy in the field. Studies like this one present important opportunities for additional field checking. B. Produce 1:24,000-scale maps of mountain shrub stands. Appendix 3 contains the 1:24,000-scale topographic maps (7.5 minute quadrangles) of mountain shrub stands in the Ecosystem. The four vegetation types shown on the maps (mountain big sagebrush, basin big sagebrush, true mountain mahogany, and Utah juniper) are described in the next section of the report. The stand of basin big sagebrush on aeolian sand in the southwestern part of the Ecosystem is the only large area of mountain shrub vegetation encountered in the project area. For the most part, the mountain shrub stands are several acres or less in size (too small to appear on the 1:100,000-scale GAP cover type map) and occur on slopes and escarpments. The exceptions are the large stand of mountain big sagebrush vegetation on Bush Rim (Freighter Gap and Monument Ridge quads), a large area of Utah juniper woodland on White Mountain in the southwestern corner of the Ecosystem (White Rocks quad) that does appear on the GAP map, and a linear stand of basin big sagebrush along a tributary of Jack Morrow Creek north of Essex Mountain (Essex Mountain quad). The mountain shrub stands are restricted to areas of substantial topographic relief within the Ecosystem: the area of Oregon Buttes and Pacific Buttes in the north-central part of the Ecosystem, the Bush Rim - Joe Hay Rim area in the 10 center, the Jack Morrow Hills - steamboat Mountain - Essex Mountain area in the central and sQuth-central parts, and the White Mountain area in the southwestern corner. No stands of mountain shrub vegetation were.observed in the Ecosystem east of the Oregon Buttes and Bush Rim, south of Freighter Gap and Steamboat Mountain, west.of the Jack Morrow Hills (except for White Mountain), or in the broad valley ~f Pacific Creek along the northern edge of the Ecosystem·. Several caveats about the maps are in order. First, the on the-ground survey work was largely restricted to the parts of the Ecosystem where review of the aerial photos suggested the presence of mountain shrub stands: the Jack Morrow Hills, the Bush Rim - Joe Hay Rim area, and ~he Oregon Butte - Pacific Butte area (Figure 2). Small stands of mountain shrub vegetation may be present in the other areas. Second, even within the area covered by the extensive survey, there may be stands of mountain shrub vegetation that do not appear on the DJ.aps, because the extensive survey was not thorough enough to reveal them. Third, the stands of vegetation shown on the 1:24,000-scale maps conform to the rather loose definition of "mountain shrub vegetation" as used in this project: vegetation that is tall enough to serve as cover or that contains species especially important as food for elk and deer. Quantitative criteria for judging whether shrub vegetation is important as cover or food, such as height of the vegetation, the minimum area of a stand, or the percentage of canopy cover of various species, probably would produce a different map. Fourth, every mountain shrub stand on the map has been assigned to a vegetation type, but for only a small number of stands is that ~ssignment based on data gathered during the intensive sampling. For the.other stands, the assignment to a vegetation type is based on distant views of the stands through binoculars, or on similarity between the sites those stands grow on and the sites that nearby, intensively sampled stands grow on. And fifth, the boundaries of the shrub stands were mapped from aerial photos (which distort features) and from field observation, often from a distance, an~ hence are approximate. Given these caveats, the value of the maps is in showing the distribution and general location of mountain shrub stands. Site-specific work involving these stands probably can only be done'confidently with site visits.

Objective 2: List the most common plant ~pecies and the diagnostic plant species in each type of mountain shrub vegetation. Seven plant associations considered to be mountain shrub vegetation (as understood in this project) were sampled and are described belo~: mountain big sagebrush-Utah snowberryjbasin wildrye, mountain big sagebrush/bluebunch wheatgrass, basin·big sagebrush/basin wildrye, basin big sagebrush/lemon scurfpea, 11 basin big sagebrush/western wheatgrass, true mo~ntain mahoganyjbluebunch wheatgrass, and. Utah juniper/bluebunch wheatgrass~ Stands of an additional plant association, the Wyoming big sagebrUsh/western whe~tgrass association, were' sampled because they appeared to be transitional between typical stands of this association (which is not mountain shrub vegetation) and mountain big sagebrush stands. Natural Heritage program ele..ment occurrence records for these associations in the Ecosystem are included in Appendix 4. Lists of common names and scientific names for plants are given in Appendix 6. Mountain big sagebrush-Utah snowberryfbasin wildrye association Landscape occurrence: Stands of the mountain big sagebrush Utah snowberryjbasin wildrye community are largely restricted to slopes with the following characteristics: aspects from north to south-southeast, slopes .steeper than 10° (mostly steeper than 15°), and substrates of residual soils or colluvium derived from sandstone, limestone, or siltstone. stands are especially well developed on escarpments below rims formed by limestone. No doubt this correlation with northerly to southeasterly slopes results partly because the strong, persistent, westerly winter winds deposit snow on those sites. Stands of this community are absent from or poorly developed on slopes underlain by claystone and mudstone. This community occurs in patqhes (often of less than 1 ha) growing on slopes in a matrix of other vegetation (Table 1). Stands often merge into stands of the basin big sagebrush/basin wildrye association and into stands of the basin wildrye association, both of which also occur in small patches at the foot of the slopes supporting the mountain big sagebrush patches. The matrix vegetation may be the Wyoming big sagebrush/bluebunch wheatgrass association, Gardner saltbush dwarf shrublands, or various grass types, such as bluebunch wheatgrass grasslands on southerly slopes. Cushion plant associations often grow on rims above the escarpm~nts that support the mountain big sagebrush stands.

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Table 1. Locations, aspects, slopes, and elevations of vegetation plots sampled in the Jack Morrow Hills Ecosystem project.

Plot Location 7.5' Map Aspect Slope Elevation (deg.) (deg.) (feet)

MOUNTAIN BIG SAGEBRUSH~UTAH SNOWBERRY/BASIN WILDRYE ASSOCIATION (1 occurrence) 1.1 T24N, R101W, Sec 33 SE1/4 SW1/4 Freighter Gap 160 23 7550 1.2 T24N, R101W, Sec 33 SE1/4 SW1/4 Freighter Gap 160 23 7550 2.1 T24N, R101W, Sec 7 SE1/4 NW 1/4 Monument Ridge 120 25 7650 2.2 T24N, R101W, Sec 7 SE1/4 NW 1/4 Monument Ridge 1·20 25 7650 4.3 T24N, R101W, Sec 5 SW1/4 Freighter Gap 140 25 7600 4.5 T24N, R101W, Sec 5 SW1/4 Freighter Gap 120 25 7600 6.1 T24N, R101W, Sec 16 NE1/4 SE;L/4 ·Freighter Gap iOO 13 7450 6.5 T24N, R101W, Sec 16 SE1/4 SW1/4 Freighter Gap 50 10 7380

7.1 T24N, R101W 1 Sec 10 SWl/4 SW1/4 Freighter Gap 90 12 7240 8.1 T24N 1 R101W, Sec 9 W1/2 NW1/ 4 · Freight~r Gap 50 20 7200 10.1 T24N, R103W 1 Sec 36 N. Packsaddle Cc;tnyon 60 17 7450 10.2 T24N, R103W, Sec 36 N. Packsaddle Canyon 0 14 -7350

14.5 T26N 1 Rl01W 1 Sec 3 SW1/4 SW1/4 Joe Hay Rim 140 25 8150 14.8 T26N, R101W 1 Sec 3 SW1/4 NW1/4 Dickie Springs 200 25 7800 20.1 T25N, R103W 1 Sec 10 S.W1/4 N. Packsaddle Canyon .120 21 7400 20.2 T25N 1 R103W 1 Sec 10 SW1/4 N. Packsaddle Canyon 120 25 7400 21.1 T24N 1 R103W 1 Sec 26 NE1/4 Essex Mountain 110 24 7600 2 2 • 4 T2 SN 1 R102W 1 Sec 3 0 SW1/'4. NW1/ 4 Essex Mountain 50 28 7560 23.1 T25N 1 R103W 1 Sec 28 NW1/4 SW1/4 Essex Mountain 80 27 7300 27.1 T24N 1 R103W, Sec 16 NW1/4 NW1/4 Essex Mountain 140 23 7750

28.1 T24N 1 R103W, Sec 14 SE1/4 Essex Mountain 40 28 7700 MOUNTAIN BIG SAGEBRUSH/BLUEBUNCH WHEATGRASS ASSOCIATION (1 occurrence)

11.3 T27N 1 R101W 1 Sec_8 NW1/4 SW1/4 Pacific Springs 30 22 7500

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Table 1 (continued). Locations, aspects, slopes, and elevations of plots sampled in the Jack Morrow Hills Ecosystem project. Plot Location 7.5' Map Aspect Slope Elevation (deg.) (deg.) (feet) BASIN BIG SAGEBRUSH/BASIN WILDRYE ASSOCIATION (1 occurrence) 2.4 T24N 1 R101W, Sec 7 SE1/4 NW 1/4 Monument Ridge 120 7 7650 5.4 T24N, R101W, Sec 8 NE1/4 SE1/4 Freighter Gap 160 25 7250

BASIN BIG SAGEBRUSH/LEMON SCURFPEA ASSOCIATION (1·occurrenc~) 25.1 T24N, R103W, Sec 18 NE1/4 NW1/4 Essex Mountain 120 8 7700 25.2 T24N, R103W, Sec 18 NE1/4 NW1/4 Essex.Mountain 50 10 7650 26.3 T24N, R103W, Sec 19 NE1/4 NE1/4 Essex Mountain 30 8 7280 26.4 T24N, R103W, Sec 20 NE1/4 NE1/4 Essex Mountain 225. 1 7260 29.1 T24N, R103W, Sec 1•4 NW1/4 SE1/4 Essex Mountain 120 10 7750 29.2 T24N, R103W, Sec 23 SW1/4 NWlJ4 Essex Mountain 340 20 7810 29.3 T24N, R103W, se·c 23 SW1/4 NW1/4 Essex Mountain 45 1 7780 29.4 T24N, R103W, Sec 22 SE1/4 NE1/4 Essex Mountain 130 23 7820 29.5 T24N, Rl03W, Sec 22 SE1/4 NE;1/4 Essex Mountain 80 11 7820 30.1 T24N, R103W, Sec 22 SE1/4 NW1/.4 Essex Mountain 360 25 7850 BASIN BIG SAGEBRUSH/WESTERN WHEATGRASS ASSOCIATION (1 occurrence) 22.3 T25N, R102W, sec 30 NW1/4 NW1/4 Essex Mountain 20 1 7430 6. 2 'T24N,. R101W, Sec 16 NE1/4 SE1/4 Freighter Gap 310 10 7380 BASIN WILDRYE ASSOCIATION (1 occurrence) 4.2 T24N, R101W, Sec 5 SE1/4 SW1/4 Monument Ridge 120 1 7590 TRUE MOUNTAIN MAHOGANY/BLUEBUNCH WHEATGRASS ASSOCIATION (1 occurrence) 3.1 T24N, R101W, Sec 32 NW1/4 SW1/4 Freighter Gap 170 33 7500 .3. 3 T24N, R101W, Sec 32 NW1/4 SW1/4 Freighter Gap 20 21 7500 22.1 T25N, R102W, Sec 30 SW1/4 NW1/4 Essex Mountain 5 25. 7550 22.2 T25N, R102W, Se.c 3 0. SW1/ 4 NW1/ 4 Essex Mountain 190 26 7550 23.3 T25N, R103W, Sec 28 SW1/4 Essex Mountain 330 27 7150 27.2 T24N, R102W, Sec 13 NE1/4 NW1/4 Essex Mountain 140 28 7750

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Table 1 (continued). Locations, aspects, slopes, and elevations of plots sampled in the Jack Morrow Hills Ecosystem project.

Plot Location 7.5' Map Aspect Slope Elevation. (deg.) (deg.) (feet)

UTAH JUNIPER/BLUEBUNCH WHEATGRASS ASSOCIATION (3 occurrences) Occurrence 1 21.3 T25N, R103W, Sec 25 NE1/4 NEl/4 Essex Mountain 220 24 7350 21.4 T25N, R103W, Sec 25 NE1/4 NE1/4 Essex Mountain 120 22 7350 24.1 T24N, R103W, Sec 8 NW1/4 NW1/4 Essex Mountain . 120 23 7500 26.1 T24N, ~103W, Sec 18 SE1/4 SE1/4 Essex Mountain 95 23 7400 26.2 T24N, R103W, Sec 17 SW1/4 SW1/4 Essex.Mountain 310. 15 7400 Occurrence 2 No plots

WYOMING BIG _SAGEBRUSH/WESTERN WHEATGRASS ASSOCIATION (1 occurrence) _ 4.1 T24N, R101W, Sec 5 SE1/4 SW1/4 Freighter <;;ap 90 13 7560 5.3 T24N, R101W, Sec 8 SW1/4 SE1/4 Freighter Gap 80 1 7250 5.5 T24N, R101W, Sec 8 SW1/4 SEl,./4 Freighter Gap 160 25 7230 9.1 T25N, R102W, Sec 16 NEl/4 SE1/4 Rock Cabin Spring 60 27 7340

WYOMING BIG SAGEBRUSH/BLUEBUNCH WHEATGRASS ASSOCIATION (1 occurrence) 5.01 T24N, R101W, Sec 8 NW1/4 SE1/4 Freighter Gap 160 20 7300 10.3 T26N, R103W, Sec 36 SW1/4 NE1/4 N. Packsaddle Canyon 250 17 7460

15 jl. Vegetation description (Table 2al: Stands of this type ·~ . possess an evergreen shrub layer from 0.6 m to 1 m tall formed by mountain big sagebrush, and a lower, mostly deciduous shrub layer (0.5 m to 0.7 m) of Utah snowberry. The lower shrub layer often contains substantial amounts of antelope bitterbrush (especially in sites high on escarpments below rims) and green rabbitbrush. Numerous other shrubs may be present. The shrub layer often is patchy, with the lower shrubs being densest in openings in the taller sagebrush layer. Basin wildrye is usually the dominant herbaceous species, often growing in openings in the sagebrush layer and forming a patchy herbaceous layer 0.5 m to 0.7 m tall. An herbaceous understory < 0.3 m tall usually contains alkali bluegrass), Nelson's needlegrass, bottlebrush squirreltail, sulphurflower buckwheat, bushy bird's beak, and western gromwell. A variety of other perennial graminoids ~nd perennial and annual forbs usually is present. · Stands of this association growing on steep escarpments ·below rims often contain patches of common chokecherry. Stands on escarpments also often merge with stands of the basin big sagebrush/basin wildrye association, and contain basin big sagebrush in the tall shrub layer and little alkali bluegrass or Nelson's needlegrass in the understory. On gentler slopes, stands transitional to the Wyoming big sagebrushjbottlebrush squirreltail association contain substantial amounts of Wyoming big sagebrush in the shrub layer and bottlebrush squirreltail in the herbaceous layer, and relatively few herbaceous species. The stand in South Packsaddle Canyon' (plot 20.1 and 20.2) may be transitional to the mountain big sagebrush/bluebunch wheatgrass association. Dynamics: The shrub layer Qften contains substantial amounts of dead sagebru~h canopy and patches of large, dead plants. Fire may rejuvenate the vegetation by opening sites for establishment of sagebrush seedlings and encouraging sprouting of Utah snowberry and antelope bitterbrush. In Box Canyon, stands were observed in which fire had removed the sagebrush layer and converted stands of this community to stands of dense, tall basin wildrye with Utah snowberry beneath. Two years after the fire, sagebrush seedlings had not appeared in the stands. Animal use: Elk were observed in stands of this association at sites 95GJ06 and 95GJ20 (Figure 2), and elk tracks and droppings were observed in stands at several sites. Acreage: The stands of this association mapped on the 1:24,000-scale maps (Appendix 3) cover ca. 2300 acres.

16 Table 2a. canopy cover of vascular plant species in plots of the 4 mountain big sagebrush-Utah snowberryjbasin wildrye association. ·'"' '·"~ ), ,'i 0. 1\ iu c- , r ~ ~"'' (\ \.' >['"i v \_, "\) ~~\' c (\ 1"1, ("\! " ,, ~ ~ Species(1) ~-~ -~~ ·'U 'llv PlSts(2)1J ~.!u .,, "' ~' 1.1 1.2 VI 2.2 4.3 4.5 6.1 6.5 7.1 8.1 9.1 10.1 10."2 TALL SHRUBS Mtn. big sagebrush 40 40 40 30 40 50 50 40 30 30 40 40 30 Utah snowberry 40 40 30 3 40 10 50 30 10 30 10 3 1 Green rabbitbrush 3 3 I 3 1 10 30 10 1 10 Antelope bitterbrush 20 30 3 20 30 1 10 IJood's rose 20 3· 1 1 3 1 10 Rubber rabbitbrush 1 3· Say's rose 3 1 Whisky currant 1 3 Spineless horsebrush Common chokecherry 20 Basin big sagebrush 3· Wyoming big sagebrush 10 Utah serviceberry Rock spiraea Limber pine Shadscale saltbush True mtn. mahogany LOIJ SHRUBS Gardner saltbush Winterfat TALL GRAMINOIDS Basin wildrye 3- 20 3 40 10 20 3 3 10 3 3 MEDIUM GRAMINOIDS ( _Alkali bluegrass 1 10 20 10 3 3 3 Nelson's needlegrass 3 10 3 10 10 10 Bluebunch wheatgrass 40 3 20 3 3 3 Indian ricegrass 1 1 3 Thickspike wheatgrass 30 Liddon sedge 10 10 Needle·and-thread Western wheatgrass 3 Nodding brome Pine needlegrass 10 10 Ditch reedgrass Letterman needlegrass Slender wheatgrass Idaho fescue SHORT GRAMINPIDS Bottlebrush squirreltail 3 3 3 1 Sandberg bluegrass 1 1 Valley sedge 10 10 10 Ross's sedge Wheeler's bluegrass FORB Sulphur buckwheat 1 1 1 1 10 3 1 3 3 1 Bushy bird's beak 3 3 3 10 1 3 3 3 10 3 3 1 3 Western gromwell 1 1 1 1 1 1 1 1 Turnip springparsely 10 10 10 10 10 3 30 10 20 1 1 Silvery lupine 1 1 1 10 20 10 Holboell's rockcress 1 1 1 1 Sego lily 1 1 1 Rocky Mtn. penstemon 1 1 3 Slender buckwheat 1 1

~ i 17 Table 2a (continued). Canopy cover of vascular plant species in plots of the mountain big sagebrush-Utah snowberryjbasin wildrye association.

Species(1) Plots(2) 1.1 1.2 2.1 2.2 4.3 4.5 6.1 6.5 7.1 8.1 9.1 10.1 10.2 Tintler milkvetch False dandelion Groundsmoke 3 Granite pricklygilia 3 Pinyon goosefoot Columbia groundsel Oblongleaf bluebells Bastard toadflax Hawksbeard 1 Purple milkvetch 3 3 20 1 10 Flowery phlox 10 3 3 1 Violet 1 1 Hat vetch 3 3 Wyoming thistle 1 Littleleaf pussytoes 3 1 Ballhead sandwort 1 3 Fremont's beardtongue Arrowleaf balsamroot Menzies's campion Prairie flax Drummond's campion Sawatch knotweed Desert prince's plume Groundsel, sp. Wyoming paintbrush Drummond's rockcress Roughseed catseye Weedy milkvetch ·4 Catseye Hatroot penstemon Hooker's sandwort Grassy deathcamas Western aster Yellow paintbrush Tansymustard Rock dandelion 1 Northern bedstraw 10 3 Carrotleaf biscuitroot 1 Bushy blazingstar 10 Larkspur Nelson tansymustard Hollyleaf clover Desert wirelettuce Desert goosefoot Spotted missionbells Hairy whitetop Douglas's dustymaiden Sharpleaf twinpod Prairie smoke Lettuce

18 Table 2a (continued). Canopy cover of vascular plant species in 4 p+ots of the mountain big sagebrush-Utah snowberryjbasin wildrye association.

Species(1) Plots(2) Average Constan- 14.5 14.8 20.1 20.2 21.1 22.4 23.1 27.1 28.1 Cover(3) cy (4) TALL SHRUBS . Mtn. big sagebrush 40 40 50 20 40 30 40 50 30 38 100 Utah snowberry 10 10 10 1 10 . 40 20 40 40 22 100 Green rabbitbrush 1 3 3 1 1 10 10 3 1 6 82 Antelope bitterbrush 30 10 1 10 10 20 40 17 64 Wood's rose 1 5 41 Rubber rabbitbrush 1 23 Say's rose 20 5 23 Whisky currant 10 3 23 Spineless hors~rush 1 18 Common chokecherry 10 20 17 14 Basin big sagebrush 10 5 14 Wyoming big sagebrush 10 5 Utah serviceberry 1 5 Rock spiraea 1 5 Linberpine 1 5 Shadscale saltbush 1 5 True mtn. mahogany 1 5 LOW SHRUBS Gardner saltbush 1 5 Winterfat 1 5 TALL GRAMINOIDS Basin' wildrye 3 3 10 10 20 3 20 10 86 MEDIUM GRAMINOIDS Alkali bluegrass 1 3 3 3 4 73 ~-~: Nelson's needlegrass 1 . 20 1 3 10 10 60 11 64 Bluebunch wheatgrass 3 1 20 3 1 10 9 59 Indian ricegrass 1 1 1 1 1 1 50 Thickspike wheatgrass 10 1 10 10 1 10 10 8 50 Liddon sedge 3 1 6 18 Needle-and-thread 1 14 Western wheatgrass 2 14 Nodding brome 3 2 9 Pine needlegrass 10 9 Ditch reedgrass 1 1 9 Letterman needlegrass 10 10 5 Slender wheatgrass 3 3 5 Idaho fescue 1 5 SHORT GRAMINOIDS Bottlebrush squirreltail 1 1 1 68 Sandberg bluegrass 1 3 1 32 Valley sedge 3 6 27 Ross's sedge 3 2 14 Wheeler's bluegrass 1 1 5 FORB Sulphur buckwheat 1 1 1 3 1 2 77 Bushy bird's beak 10 .10 10 10 10 6 82 Western gromwell 3 1 1 3 3 1 1 73 Turnip springparsely 10 30 10 12 64 Silvery lupine 3 1 1 1 4 59 Holboell's rockcress 1 1 1 55 Sego lily 1 1 45 Rocky Mtn. penstemon 3 1 1 1 1 50 Slender buckwheat 1 3 3 3 10 3 45 Tini>er milkvetch 1 3 1 1 1 so False dandelion 1 1 41 ~ 19 Table 2a (continued). Canopy cover of vascular plant species in plots of the mountain big sagebrush-Utah snowberryjbasin wildrye association.

Species(1) Plots(2) Average constan 14.5.14.8 20.1 20.2 21.1 22.4 23.1 27.1 28.1 Cover(3) cy (4)

Groundsmoke 3 2 36 Granite pricklygilia 1 36 Pinyon goosefoot 1 27 Columbia groundsel 1 27 Oblongleaf bluebells 1 23 Bastard toadflax 1 18 Hawksbeard 1 18 Purple milkvetch 7 23 Flowery phlox 4 18 Violet 1 23 Mat vetch 2 23 Wyoming thistle 1 23 Littleleaf pussytoes 3 2 18 Ballhead sandwort 2 14 · Fremont's beardtongue 1 18 Arrowleaf balsamroot 3 2 18 Menzies's campion 1 18 Prairie flax 1 14 Drummond's campion 1 9. Sawatch knotweed 1 9 Desert prince's plume 1 14 Groundsel, sp. 1 14 Wyoming paintbrush 1 9 Drummond's rockcress 1 14 Roughseed catseye 1 14 Weedy milkvetch 1 9 Catseye 1 9 Matroot penstemon 1 9 Hooker's sandwort 1 9 Grassy deathcamas 1 5 Western aster 1 9 Yellow paintbrush 1 5 Tansynustard 1 9 Rock dandelion 1 9 Northern bedstraw 7 9 Carrotleaf biscuitroot 1 9 Bushy blazingstar .6 9 Larkspur 1 9 Nelson tansymustard 1 9 Hollyleaf clover 1 5 Desert wirelettuce 1 5 Desert goosefoot 1 5 Spotted missionbells 1 5 Hairy whitetop 1 5 Douglas's dustymaiden 1 5 Sharpleaf twinpod 1' 5 Prairie smoke , 5 Lettuce 1 5 (1) Species are identified by common name and are organized by the life-form classes described in Appendix 2. Scientific names are listed in Appendix 6. (2) The cover values in the table refer to the canopy cover classes shown in Appendix 2. (3) The average cover is calculated only for the plots containing the species. <4> Constancy is the percent of plots containing the species •

• 20 Mountain big sagebrush/bluebunch wheatgrass association Landscape position: The single stand of this association was sampled on the northeast face of Pacific Butte (Table 1), where the sagebrush vegetation forms a matrix containing stands of aspen and limber pine woodland. At the foot of the slope, the mountain big sagebrush vegetation merges into Wyoming big sagebrush vegetation. At the top of the slope, the mountain big sagebrush vegetation merges into bluebunch wheatgrass vegetation.

Vegetation description (Table 2b): Mountain big sagebru~h forms an open shrub layer < 0.5m tall. A small amount of Utah snowberry is present, and aspen seedlings or sprouts are present near stands of aspen trees. Many of the shrubs have substantial amounts of dead canopy, but dead shrubs are uncommon. The main herbaceous species in the sparse understory are bluebunch wheatgrass, Ross's sedge, needlegrass, rosy pussytoes, silvery lupine, and flowery phlox. Many other forbs are present. Dynamics: The presence of aspen seedlings or sprouts on the edges of the sagebrush stands, and the presence of mountain big sagebrush shrubs in the understories of some aspen stands, suggest that aspen woodland will replace some of the mountain big sagebrush vegetation in the absence of fire. ( Animal use: No signs observed. Acreage: The area of the stand is estimated at ca. 400 acres. The Jack Morrow Hills Ecosystem may contain more acreage of this plant association than this study suggests. This association has a shorter shrub canopy and less cover of palatable browse species than do the other types sampled, so little _attention was paid to this type during the study. For example, plot 20.2 (Table 2a) -may represent a stand in South Packsaddle Canyon (North Packsaddle Canyon quad) intermediate between this mountain big sagebrush/bluebunch wheatgrass association and the mountain big sagebrush~utah snowberryjbasin wildrye association.

) 21 Table 2b. Canopy cover of vascular plant species in the plot of the mountain big sagebrush/bluebunch wheatgrass association.

Species(1) Plot(2) 11.3 TREES Quaking aspen 1 TALL SHRUBS Mtn. big sagebrush 30 Utah snowberry 3 MEDIUM GRAMINOIDS Nelson's needlegrass 3 ·Bluebunch wheatgrass 10 Liddon sedge 1 Needle-and-thread 1 SHORT GRAMINOIDS Ross's sedge 3 Wheeler's bluegrass 1 1 FORB Western gromwell 1 Sego lily 3 ~ ~ Rocky Mtn. penstemon: 1 Slender buckwheat 1 False dandelion 1 Pinyon goosefoot 1 Purple milkvetch 1 Flowery phlox 1 Mat vetch 3 Arrowleaf balsamroot 1 Desert prince's plume 1 Groundsel, sp. 1 Roughs~ed catseye 1 Matroot penstemon 1 Yellow paintbrush 1 Rock dandelion 1 Lettuce 10

22 Basin biq saqebrush/basin wildrye association. Landscape position: stands of this association grow on southeast-facing escarpments (plots 2 • 4 and 5. 4) ·, especially at the foot of the escarpment, and in valley bottoms on terraces above t~e floodplain. stands on escarpments merge into mountain big sagebrush-Utah snowberryjbasin wildrye stands and bluebunch wheatgrass stands on the escarpment, and into Wyoming big sagebrushjbottlebrush squirreltail stands or Gardner saltbush stands on the adjacent valley floors. Stands in stream valleys may adjoin herbaceous riparian vegetation on the floodplain, and merge into greasewood stands on higher terraces or into Wyoming big sagebrush or Gardner saltbush vegetation away from the stream.

Vegetation description (Table 3, 4al: Basin big sagebrush forms a shrUb layer up to 1 meter tall. Utah snowberry usually is present, and may contribute substantial cover on escarpments. Green rabbitbrush also is present, but in smaller amounts. Stands high on escarpments may contain antelope bitterbrush, and stands at the foot of slopes or in valley bottoms may contain mountain silver sagebrush. Dead saqebrush canopy may be common. Basin wildrye contributes substantial cover and often is the most common herbaceous species present. Bluebunch wheatgrass may contribute Substantial cover on esqarpments. Other graminoids and·forbs, especially bottlebrush squirreltail and turnip (' springparsely, often are present but contribute little cover. Dynamics: This apparently is a persistent community. In the absence of fire, the basin big sagebrush shrubs may become decadent and the shrub layer come ~o include substantial amounts of dead canopy. Fire probably encourages sprouting of Utah snowberry and antelope bitterbrush, and allows cover of basin wildrye to increase. Basin big sagebrush does not sprout after fire, but seedlings may bec:ome established and eventually return a tall shrub canopy to the stand. Animal use: .No signs observed. Acreage: Less than 100 acres of this association has been mapped in the Ecosystem (Appendix 3), along a valley tributary to Jack Morrow Creek north of Essex Mo.untain (Essex Mountain quad), at the foot of the escarPment below Bush Rim (Monument Ridge and Freighter Gap quads), and on ·slopes in Alkali Draw near Bush Rim (Freighter Gap quad). Additional small, unmapped stands probably occur in the Ecosystem.

23 Table 3~ Canopy cover of vascular plant species in the basin wildrye plot. This plot occurred on a bench at the foot of Bush Rim, within a stand of the mountain big sagebrush-Utah snowberryjbasin wildrye association.

Species(1) Plot(2) 4.2 TALL SHRUBS Utah snowberry 10 Wood's rose 1 Wyoming big sagebrush 1 TALL GRAMINOIDS Basin wildrye 90 MEDIUM GRAMINOIDS Big bluegrass 10 Weste~n wheatgrass 3 SHORT GRAMINOIDS Mat rwhly 3 Sandberg bluegrass 1 Needle-leaf sedge 1 FORBS Rocky Mtn penstemon 1 Cinquefoil 1 Povertyweed 1 Desert stickseed 1 Rock dandelion 1 Hollyleaf clover 1 Mat vetch 1 Field pennycress 1 (_~~ Yellow salsify 1 .Purple milkvetch 1 Wyoming paintbrush 1 Common yarrow . 1 Western aster 1 Pinyon goosefoot 1 Groundsmoke 1 Rod hal imolobos 1 Wyoming thistle 1 Tansymustard 1

(.1) Species are identified by common name and are organized by the life-form classes described in Appendix 2. Scientific names are listed in Appendix 6. (2) The cover values in the table refer to the canopy cover. classes shown in Appendix 2.

24 Table 4a. Canopy cover of vascular plant species ' in the basin 4 big sagebrush/basin wildrye.plots.

Species(1) Plots(2) Average Cons tan- 2.4 5.4 Cover(3) cy(4) TALL SHRUBS Basin big sagebrush 30 30 30 100 Utah snowberry 3 40 2.2 100 Green rabbitbrush 3 1 2 100 Mtn. silver sagebrush 20 20 50 Antelope bitterbrush 10 10 50 Rubber rabbitbrush 10 10 50

LOW SHRUBS Gardner saltbush 1 1 50

TALL GRAMINOIDS Basin wildrye 40 10 25 100

MEDIUM GRAMINOIDS Indiari ricegrass 1 1 1 100 Bluebunch wheatgrass 10 10 50 Alkali bluegrass 3 3 50 Western wheatgrass 3 3 50

SHORT GRAMINOIDS Bottlebrush squirreltail 3 3 3 100

FORBS Turnip springparsely 3 10 7 100 Bushy bird's beak 1 3 2 100 Holboell's rockcress 1 1 1 100 False dandelion 1 1 50 Sego lily 1 1 50 Timber milkvetch 1 1 50 Wyoming thistle 1 1 50 Nelson's tansy 1 1 50 Sulphurflower buckwheat 1 1 50 Western gromwell 1 i 50 Gran·ite pricklygilia 1 1 50 Pinyon goosefoot '1 1 50 Desert goosefoot 1 1 50

( 1) Species are identified by common name and are organized by the life-form classes described in Appendix 2. Scientific names are listed in Appendix 6. (2) The cover values in the table refer to the canopy cover classes shown in Appendix 2. (3) The average cover is calculated only for the plots containing the species. (4) Constancy is the percent of plots containing the species. ~ 25 Basin ~iq saqe~rusb/lemon scurfpea association. Landscape position: Large stands of this plant association occur on aeolian sand in the southwestern part of the Ecosystem. Slopes range from essentially flat to 20°, and aspects are primarily northeast to south (Table 1). The largest stand, south of steamboat Rim, is on the rolling surface of a field of stabilized sand dunes. Smaller stands in the upper parts of valleys draining north from Steamboat Rim occur on valley sides bottoms, where the sand has accumulated. · Vegetation description (Table 4bl: Basin big sagebrush forms a shrub layer up to 2.5-meters tall. Rubber rabbitbrush forms a slightly shorter shrub layer (to 1 meter tall) and may dominate patches covering up to several hundred square meters. Green rabbitbrush and Utah snowberry often are present in the understory. In relatively mesic sites, the tall shrub layer may contain substantial amounts of Utah serviceberry and common chokecherry, and the lower shrub layer may contain substantial amounts of whisky currant and antelope bitterbrush. The .understory is characterized by the presence of the rhizomatous forb lemon scurfpea, often as.the dominant species. Thickspike wheatgrass, another rhizomatous species (or western wheatgrass, a morphologically and ecologically similar species) usually is present and may contribute substantial cover. Other species usually present in small amounts are Indian ricegrass, needle-and-thread grass,. desert stickseed, hoary aster, and desert goosefoot. Dynamics: In the absence of fire, this apparently is a persistent community. In Box Canyon, fires apparently have converted basin big sagebrush/lemon scurfpea vegetation to green rabbitbrush - lemon scurfpea vegetation. The vegetation in the areas burned in 1993 was low (< O.J~eters tall) and composed primarily of green rabbitbrush and lemon scurfpea (both species that are usually present in the basin big sagebrush stands and that sprout· from be.low-ground parts) with· few other species. Burned sagebrush stumps were abundant, but no sagebrush seedlings were observed. Animal use: This tall sagebrush vegetation is well known as hiding cover and crucial calving habitat for elk, and the palatable shrubs in these stands (Utah serviceberry, antelope bitterbrush, Utah snowberry, currant) usually were moderately to heavily browsed. Plot 2 f5. 4, south o.f Essex Mountain, ·contained rabbit droppings that were identified by Todd Katzner of the University of Wyoming Department of Zoology and Physiology as probably belonging to pygmy rabbit (Brachylagus idahoensis).

26 Table 4b. Canopy cover of vascular plant species in plots of the basin big sagebrushjlempn scurfpea association.

Species(1) Plots(2) Average Constan 25.1 25.2 26.3 26.4 29.1 29.2 29.3 29.4 29.5 30~1 Cover(3) cy (4) TALL SHRUBS ! Basin big sagebrush 50 30 40 40 40 20 40 30 40 30 36 100 Rubber .rabbitbrush 1 30 3 1 40 40 40 20. 1 20 90 Green rabbitbrush 3 10 . 10 10 10 1 1 1 6 80 Utah snowberry 1 1 30 20 20 30 17 60 Spineless horsebrush 1 1 1 20 6 40 Antelope bitterbrush 1 1 1 1 40 Whisky currant 1 3 2 30 ( Common chokecherry 40 20 30 20 Mountain big sagebrush 10 1 6 20 . Say's rose 3 3 3 20 Utah serviceberry 30 30 10 TALL GRAMINOIDS Basin wildrye 3 3 10 l MEDIUM GRAMINOIDS Thickspike wheatgrass 3 10 20. 10 30 20 10 20 1 13 100 Indian ricegrass 1 3 1 10 1 1 1 1 ,.. 2 100 Needle-and-thread 1 1 1 1 1 3 3 1 1 90 Nelson's needlegrass 1 1 10 Alkali bluegrass 1 10 Crested wheatgrass ,. 10 SHORT GRAMINOIDS Needle-leaf sedge 20 20 10 Bottlebrush squirreltail 1 10 FORBS Lemon scurfpea 30. 4{) 30 20 so 20 20 30 2_0 26 100 Desert stickseed 1 1 1 1 1 1 1 1 80 Hoary aster 1 1 1 1 1 1 1 80 Desert goosefoot 3 3 1 1 1 2 70 Silvery lupine 1 30 7 so Holboell's rockcress 1 1 40 Veiny dock 1 1 40 Silky catseye 1 1 30 Western gromwell 1 1 1 30 Fremont's goosefoot 3 2 20 Sulphurflower buckwheat 3 2 20 Rocky Mtn. penstemon 1 20 Grounclsmoke 3 3 10 Granite pricklygilia 1 10 Turnip springparsely 1 10 Slender buckwheat 1 10 Bastard toadflax 1 10 Wyoming paintbrush 1 10 Rock dandelion 1 10 False Solomon's seal 1 10 Desert wirelettuce 1 10 (1) Species are identified by common name and are·organized by the life-form classes described in Appendix 2. Scientific names are listed in Appendix 6. ( 2) The cover values in the table re·fer to the canopy cover classes shown in Appendix 2 .• (3) The average cover is calculated only for the plots containing the species. (4) Constancy is the percent of plots containing the species.

27 Acreage: The area mapped as the basin big sagebrush/lemon scurfpea association on the 1:24,000-scale maps (Appendix 3) covers 19,155 acres. Basin biq saqebrush/western wheatqrass association. Landscape oosition: Two stands of this association were sampled (Table 1). The first·was a single patch at site 6 on the mesa east of Alkali Draw (Freighter Gap quad), covering ca. 250 square meters on·a northwest-facing, 10° slope in a shallow draw. The other was a stand comprising several· patches of several h~ndred, square meters each at site 22 (Essex Mount.ain q\lad) in a broad valley bottom on sandy colluvium. Adjoining vegetation at the first site was the Wyoming big sagebrush/western wheatgrass association. At site 6, the adjoining vegetation on westerly slopes and the mesa above was Gardner saltbush - birdsfoot sagewort,.with western wheatgrass in the bottom of the draw. The east-facing slope across the draw supported a mountain big sagebrush-Utah snowberryjbasin wildrye stand (plot 6.1). Vegetation description (Table 4c): Basin big sagebrush forms a patchy shrub layer 1 to 1.5 meters tall. Lower shrubs may be present, especially Utah snowberry and green rabbitbrush, and may contribute substantial cover. The herbaceous understory contains substantial amounts of / ~ thickspike wheatgrass (which usually dominates) and smaller ' amounts of alkali bluegrass, bottlebrush squirreltail, bushy bird's beak, Holboell's rockcress,.and several other grasses·and forbs. · · Dynamics: This association apparently is persistent in the absence of fire or other disturbance. Animal use: Elk droppi;ngs were preserit·at site 22, as were rabbit droppings identified by Todd Katzner of the University of Wyoming Department of Zoology and Physiology as probably being from pygmy rabbit (Brachylagus idahoensis). Acreage: The area mapped on the 1:24,000-scale quad covers ca. 5 acres.

28 Table 4c. Canopy cover of vascula+ plant species in the plot of the basin big sagebrush/western wheatgrass association.

Species(1) Plots(2) 22.3 6.2 TALL SHRUBS Basin big sagebrush 60 40 Utah snowberry 3 10 Green rabbitbrush 20' Wyoming big sagebrush 3 Spineless horsebrush 1 MEDIUM GRAMINOIDS Thickspike wheatgrass 10. 40 Alkali bluegrass 1 3 Nelson's needleqra~s 3 Indian ricegrass 1 Bluebunch wheatgrass 1 SHORT GRAMINOIDS Bottlebrush squirre11tail 1 3 Muttongrass J 10 FORBS Bushy bird's beak 10 3 ,. Rocky Mtn. penstemon 1 1 Holboell's rockcress 1 1 Nodding buckwheat 10 Timber milkvetch 3 Granite pricklygilia 1 Groundsmoke 1 Desert stickseed 1 Purple milkvetch 1 Prairie flax 1 Yellow paintbrush 1 Textile onion 1 Bastard toadflax 1 Hollyleaf clover 1 Larchleaf beardtongue 1

(1) Species are identified by common.name and are organized by the life-form classes described in Appendix 2. Scientific names are listed in Appendix 6. (2) The cover values in the table refer to the canopy cover classes shown in Appendix 2.

29 \

True mountain mahoqany/~lue~unch wheatqrass association. Landscape position: This association occurs as small stands covering up to several acres on slopes steeper than 20°, with a variety of aspects (Table 1). All of the stands sampled during this project or observed in the extensive survey of the Ecosystem occurred on or near outcrops of sandstone bedrock. These stands usually occur in a matrix of Wyo~ing big sagebrushjbluebunch wheatgrass v~getation or bluebunch wheatgrass vegetation on the slopes. Vege~ation on the mesas above may be Wyoming big sagebrushjbluebunch wheatgrass, blu.ebunch wheatgrass, or cushion plant vegetat.i,.on. Mountain mahogany stands on easterly and northerly slopes often adjoin stands of the mountain big sagebrush-Utah snowberryjbasin wildrye association. The mountain mahogany stands usually merge downslope into Wyoming big sagebrushjbottlebrush squirreltail·stands or Gardner saltbush vegetation. Vegetation description (Table 51: Stands of this association feature a shrub layer dominated by true mountain mahogany, which usually is ~ 1 meter tall but in some stands may be < 0.5 meter tall. This shrub layer usually is sparse. Lower shrubs, especially Wyoming big sagebrush., Utah snowberry, spineless horsebrush, green rabbitbrush, and rubber rabbitbrush, usually are present in small amounts. Several other shrubs (antelope bitterbrush, Utah serviceberry, mountain big sagebrush, - and others) may be present. · The herbaceous layer is also usually sparse and contains bluebunch wheatgrass, Indian ricegrass, Wyoming thistle, slender buckwheat, turnip springparsely, and bushy bird's beak. Many other forbs may be present in the stand. Dynamics: This apparently is a persistent community in the absence of fire or other disturbances. True mountain mahogany and utah snowberry sprout after fire, but big sagebrush does not, so fire would decrease the cover of sagebrush and increase the cover of other shrubs, at least temporarily. Fire may be important in rejuvenating the sprouting shrubs.

Animal use: Evidence o~ browsing was observed on the palatable shrubs (mountain mahogany, antelope bitt~rbrush, Utah serviceberry) in most of the stands. Elk and deer droppings were observed in most of the stands. Acreage: The true mountain mahogany stands mapped on the 1:24,000-scale maps (Appendix 3) cover less than 100 acres. Additional stands may be present in the Jack Morrow Hi~ls Ecosystem, although mountain mahogany stands are relatively easy to pick out on aerial photographs and are noticeable in the field, so additional, unmapped stands probably are small.

30 4---, Table 5. Canopy cover of vascular plant species in the true' mountain mahogany plots.

Species(1) Plots(2) Average Constan- 3.1 3.3 22.1 22.2 23.3 27.2 Cover(3) cy(4) TALL SHRUBS True mtn. mahogany 30 30 20 20 10 10 ~0 100 Wyoming big sagebrush 3 3 3 20 1 3 6 100 Utah snowberry 10 10 1 1 3 1 4 100 Spineless horsebrush· 1 10 10 1 1 5 83 Green rabbitbrush 3 10 3 3 3 4 83 Rubber rabbitbrush 1 3 3 1 3 2 83 Antelope bitterbrush 3 1 10 3 4 67 Utah serviceberry 1 1 1 1 50 Mounta.in big sagebrush 10 3 7 33 Shadscale saltbush 1 1 33 Spiny hopsage 1 17 Say's rose 1 17 LOW SHRUBS Black sagebrush 1 3 2 33 TALL GRAMINOIDS Basin wildrye 20 11 33 MEDIUM GRAMINOIDS Bluebunch wheatgrass 1 30 10 3 1 9 83 Indian ricegrass .3 3 10 3 10 6 83 Thickspike wheatgrass 1 3 1 1 2 67 Needle-and-thread 1 1 1 33 Alkali bluegrass 10 3 7 33 Nelson's needlegrass 1 1 17 SHORT GRAMINOIDS Bottlebrush squirreltail 33 -- 17 Sandberg bluegrass FORBS Wyoming thistle 1 1 1 1 1 83 Slender buckwheat 3 3 1 3 1 2 83 Turnip springparsely 3 10 .3 1 3 4 83 Bushy bird's beak 1 10 1 1 3 83 Hooker's sandwort 1 1 1 67 Desert prince's plume 1 50 Shortstem buckwheat 1 1 1 50 Bastard toadflax 3 3 2 50 Desert goosefoot 1 1 50 Nuttall's goldenweed 1 1 1 50 Sulphurflower buckwheat 1 1 1 50 Granite pricklygilia 3 2 33 Hoary aster 1 1 33 Prairie flax 1 1 33 Larchleaf beardtongue 1 33 Sego lily 1 33 Hood's phlox 1 33 Holboell's rockcress 1 33 Wyoming paintbrush 1 33 Rocky Mtn. penstemon 1 33 Hawksbeard 1 33 Yellow salsify 1 17 Sharpleaf twinpod 1 17 Fremont's beardtongue 1 17 Nuttall's povertyweed 1 17 Large-fruited milkvetch 1 17 Weedy milkvetch 1 17 Littleleaf pussytoes 17 Ballhead sandwort 1 17 ~ 31 Table 5 (continued). Canopy cover of vascular plant species in the true mountain mahogany plots.

SpeciesC1) Plots(2) Average Constan- 3-1 3.3 22.1 22.2 23.3 27.2 Cover(3) cy(4) Catseye 17 Desert stickseed 17 Carrotleaf biscuitroot 17 Nodding buckwheat 17 Golden buckwheat 17

(1) Species are identified by common name and are organized by the .life-form classes described in Appendix 2. Scientific names are listed in Appendix 6. (2) The cover values in the table refer to the canopy cover classes shown in Appendix 2. (3) The average cover is calculated only for the plots containing the species. (4) Constancy is the percent of plots containing the species.

32 Utah juniper/bluebunch wheatgrass association. Landscape position: Two occurrences of the Utah juniper/bluebunch wheatgrass plant association lie within the Jack Morrow Hills Ecosy~tem. Occurrence 1 includes stands from the north side of Jack Morrow Creek valley (east of Marne Spring) ,southwest to Essex Mountain. These stands are on slopes with angles of 10° to over 20° facing mainly south and east. All stands visited in this occurrence grew on sandstone-derived soils, and sandstone outcrops were common. Occurrence 2 includes stands on the east side of White Mountain north of White Rocks, on slopes facing primarily east. No information was collected from occurrence 2. Utah juniper stands adjoin a variety of other vegetation types. Wyoming big sagebrush/bluebunch wheatgrass stands, black sagebrush/bluebunch wheatgrass stands, and bluebunch wheatgrass stands usually occur with the juniper stands on slopes. Mesas above may support Wyoming big sagebrush/bluebunch wheatgrass stands or bluebunch wheatgrass stands or, on limestone rims, cushion plant stands. The vegetation downslope from juniper stands may be Wyoming big sagebrush stands, basin big sagebrush stands, or Gardner saltbush stands. Vegetation description (Table 6): Stands of this association are rich in species but the vegetation is usually sparse. Utah juniper forms a patchy shrub layer 3 to 5 meters tall. A sparse iow shrub layer (< 0.5 meter tall) includes Wyoming big sagebrush and, in most stands, antelope bitterbrush, green rabbitbrush, and black sagebrush. The low shrub layer may contain a variety of additional species. The sparse herbaceous understory includes thickspike wheatgrass, needle-and-thread grass, Indian ricegrass, sulphurflower buckwheat, thrifty goldenweed, and bushy bird's beak. Other species that usually occur in the understory are alkali bluegrass, bluebunch wheatgrass, bottlebrush squirreltail, Sandberg bluegrass, hoary aster, silky catseye, slender buckwheat, timber milkvetch, and ballhead sandwort. Numerous additional forbs may occur. Dynamics: No information was collected on vegetation dynamics in this type. Animal use: Deer and elk droppings were common in all of the stands visited. Elk were observed in the juniper stands at sites 21 and 24 (both on the. Essex Mountain quad). Acreaae: Juniper stands mapped on the 1:24,000-scale maps (Appendix 3) cover ca. 800 acres: 300 acres in occurrence 1 and 500 acres in occurrence 2. -- 33 Table 6. Canopy cover of vascular plant species in the Utah "4 juniper plots in occurrence 1. Occurrence 2 was not sampled.

Spe~ies(1) Plots(2) Average C6nstan- 21.3 21.4 24.1 26.1 26.2 . Cover(~) cy<4> TREES Utah juniper 10 10 10 20 20 14 100 TALL SHRUBS Wyoming big sagebrush 10 10 10 3 3 7 100 Antelope bitterbrush 1 1 1 10 3 80 Green rabbitbrush 1 1 3 3 2 80 Spineless horsebrush 1 1 1 60 Utah snowberry 3 3 3 40 Rubber rabbi tbrush 1 41f Shadscale saltbush 1 40 Greasewood 1 20 LOW SHRUBS Black sagebrush 3 10 3 3 5 80 Winterfat, 1 1 1 60 MEDIUM GRAMINOIDS Thickspike wheatgrass 20 1 3 1 3' 6 100 Needle-and-thread 1 1 1 1 10 3 100 Indian ricegrass 1 3 1 1. 1 1 100 Bluebunch wheatgrass 20 10 1 1 8 80 Alkali bluegrass 10 1 1 1 3 80 Saline wildrye 3 1 2 40 Crested wheatgrass 1 20 SHORT GRAMINOIDS Sandberg bluegrass 3 2 80 t Bottlebrush squirreltail 1 1 80 FORBS Bushy bird's beak 10 10 10 3. 3 7 100 Sulphurflower buckwheat 1 1 1 1 1 1 100 Thrifty goldenweed 1 1 1 1 1 1 100 Slender buckwheat 1 1 3 3 2 80 Tinmer milkvetch 3 1 1 1 2 80 Hoary aster 1 1 1 1 1 80 Silky catseye 1 1 1 1 80 Ballhead sandwort 1 1 1 1 80 Lemon scurfpea 1 1 1 1 60 Douglas's dustymaiden 1 1 1 1 60 Holboell's rockcress 1 1 1 60 Large-fruited milkvetch 1 1 1 60 Sharpleaf twinpod 1 1 1 1 60 Golden buckwheat 1 1 1 60 Rocky Mtn. penstemon 1 1 60 Granite ·pricklygil ia 3 2 40 Matted buckwheat 1 40 Nodding buckwheat 1 40 Desert wirelettuce 1 1 40 Compact gilia 1 1 40 Desert stickseed 1 40 Bastard toadflax 1 40 Pinyon goosefoot 1 40 Hooker's sandwort 1 1 40 Shortstem buckwheat 1 1 1 40 Spiny milkvetch 1 1 1 40 Turnip springparsely 3 3 20 Silvery lupine 3 3 20

[ ~ 34 Table_6 (continued). Canopy cover of vascular plant species in (_; the Utah juniper plots.

Species(1) Plots(2) Average Constan 21.3 21.4 24.1 26.1 26.2 Cover(3) cy(4) Musk phlox 20 Larchleaf beardtongue 20 Weedy milkvetch 20 Hood's phlox 20 Desert prince's plume 20 Littleleaf pussytoes 20 Columbia groundsel 1 20 Grounclsel, sp. 1 20 Plains pricklypear 1 20 Nuttall's goldenweed 1 20 Wyoming paintbrush 1 20 Wyoming thistle 1 20 Tansymustard 1 20 Spoonleaf milkvetch 1 20 Prairie flax 1 20 Sego lily 1 20 Arrowleaf balsamroot 1 20

f 35 Wyoming big sagebrush/western wheatgrass association. In most stands of this association, the vegetation is too short and lacking in palatable shrubs to be considered mountain shrub vegetat'ion, as defined in this project. Several stands were sampled and are mapped because the shrub layer was unusually tall or because the stands merged into mountain shrub stands. Landscape position: Stands of this association typically occupy the lower parts of easterly slopes, benches, and valley bottoms, and typically cover from several hundred to 1000 square meters. Sample plots were located on nearly flat sites to 30° slopes with aspects from northeast to southeast (Table 1). Adjacent vegetation typically is mountain big sagebrush-Utah snowberryjbasin wildrye higher on the slopes, and Wyoming big sagebrushjbottlebrush squirreltail or Gardner saltbush vegetation on mesas above and valley bottoms below. Vegetation description (Table 7al: Wyoming big sagebrush forms a shrub layer ca. 0.5 meter tall (although patches of taller shrub may be present). Green rabbitbrush, Utah snowberry, and rubber rabbitbrush form a lower shrub layer ca. 0.3 m tall. The herbaceous understory contains a substantial amount of western wheatgrass or thickspike wheatgrass, and one of these species often dominates. (These two rhizomatous species are similar morphologically and ecologically, and thickspike wheatgrass probably is commonly mistaken for the better-known western wheatgrass.) Alkali bluegrass is present and may codominate. Indian ricegrass, bottlebrush squirreltail, and bushy bird's beak contribute little cover, and a variety of additional grasses and forbs may be present. Dynamics: This association appears to be persistent in the absence of fire. · Animal use: Burrows were observed in some stands. Acreage: The area mapped as this association on the 1:24,000-scale maps (Appendix 3) covers less than 40 acres. The association doubtless covers a substantial area in the Jack Morrow Hills Ecosystem, and appears to be a minor type simply because only stands with unusually tall shrub layers, or stands next to mountain shrub stands, were sampled.

36 Table 7a. Canopy cover of vascular plant species in plots of the wyoming big sagebrush/western wheatgrass association.

>f ~'I...... >R. ~ obi ..w Species(1) ·~ Plots(2) Average constan- 4.1 5.3 5.5 Cover(3) cy(4) TALL SHRUBS Wyoming big sagebrush 30 50 30 37 100 Green rabbitbrush 10 10 1, 7 100 Utah snowberry 10 3 1 5 100 Rubber.rabbitbrush 10 3 1 5 100 Three-tip sagebrush 1 1 33 Spineless horsebrush 1 33 LOW SHRUBS Gardner saltbush 33 Low sagebrush 33 TALL GRAMINOIDS Basin wildrye 1 67 MEDIUM GRAMINOIDS· 1 Alkali bluegrass 10 20 1 10 100 Indian ricegrass 1 1 1 1 100 Thickspike wheatgrass 20 10 15 67 Western wheatgrass 20 f 20 33 Bluebunch wheatgrass . 3· 3 33 Nelson's needlegrass 3 3 33 SHORT GRAMINOIDS Bottlebrush squirreltail 3 1 3 2 100 Sandberg bluegrass 3 3 33 FORBS Bushy bird's beak 10 3 5 100 Timber m\lkvetch 1 1 1 67 Purple milkvetch 3 3 33 Bastard toadflax 3 3 33 Prairie flax 1 33 Yellow paintbrush 1 33 Textile onion 1 33 Holboell's rockcress 1 33 Rocky Mtn. penstemon 1 33 Larchleaf beardtongue 1 33 Hood's phlox 1 33 Wyoming paintbrush 1 33 Western aster 1 33 Lemon scurfpea 1 33 Sego lily 1 33 Wyoming thistle 1 33 Granite pricklygilia 1 33 Sulphurflower buckwheat 1 33 Turnip springparsely 1 33 Western gromwell 1 33 Rock dandelion 1 33 Slender buckwheat 1 33 Hooker's sandwort 1 33 Mat vetch 1 1 33 (1) Species are identified by common name and are organized by the life-form classes described in Appendix 2. Scientific names are listed in Appendix 6. (2) The cover values in.the table refer to the canopy cover classes shown in Appendix 2. (3) The average cover is calculated only for the plots containing the species. (4) constancy is the percent of plots containing the species.

37 Wyominq ~iq saqebrush/~lue~unch wheatqrass association. The vegetation in this association is too short for stands to qualify as.mountain shrub vegetation, as the term is used in this project. Nevertheless, two stands were sampled because they contained substantial amounts of antelope bitterbrush and therefore might be important sources of food for wildlife. Landscape position: This association typically occupies sites exposed to the wind: southerly and westerly slopes, or the upper.parts of easterly slopes. Two stands were sampled on ca. 20° slopes facing south and west (Table 1). Adjacent vegetation is basin big sagebrush shrub stands or grass stands (basin wildrye or western wheatgrass) in draws downslope, and cushion plant or Wyoming big sagebrush vegetation upslope. Vegetation description (Table 7bl: Wyoming,big sagebrush, antelope bitterbrush, and green rabbitbrush form a sparse shrub layer 0.2 meter to 0.3 meter tall. Small amounts of other shrubs may be present. The shrub layer may contain substantial amounts of dead canopy. Bluebunch wheatgrass dominates the herbaceous layer, and small amounts of other grasses and forbs usually are present, especially turnip springparsely, granite pricklygilia, bushy bird's beak, timber milkvetch, Holboell's rockcress, and ( sulphurflower buckwheat. Dynamics: This apparently is a persistent community. Animal use: Deer or antelope tracks and droppings were present in the sampled stands. Acreage: The area of this type mapped on the 1:24,000-scale maps (Appendix 3) covers less than 20 acres. This association doubtless is more widespread in the Jack Morrow Hills Ecosystem, and appears to be a minor type beqause only stands with substantial antelope bitterbrush cover that occurred near mountain shrub stands were sampled. ·

38 Table 7b. Canopy cover of vascul.ar plant species in plots of the ( Wyoming big sagebrush/bluebupch wheatgrass association.

Species(1) Plots(2) 5.1 . 10.3 TALL SHRUBS Wyoming big sagebrush 20 20 Antelope bitterbrush 10 20 Green rabbitbrush 10 10 Spineless horsebrush 1 Mountain big sagebrush Utah snowberry Rubber rabbitbrush TALL GRAMINOIDS Basin wildrye I.' MEDIUM· GRAMINOIDS I Bluebunch wheatgrass 30 10 Thickspike wheatgrass 3 Indian ricegrass SHORT GRAMINOIDS Bottlebrush squirreltai( FORBS Turnip springparsely 3 10 Granite pricklygilia 1 3 Bushy bird•s beak 3 1 Timber milkvetch 1 1 i L - • Holboell '·S rockcress 1 1 ------· -- -- ~ Sulphurflower buckwheat 1 1 Hooker's sandwort 3 Douglas's dustymaiden Spoonleaf milkvetch Desert prince's plume Pinyon goosefoot Thrifty goldenweed Shortstem buckwheat Golden buckwheat False dandelion 1 Wyoming thistle 1 Mat vetch . 1 Prairie flax Sego lily Silvery lupine Desert wirelettuce Slender buckwheat Fremont's beardtongue

(1) Species are identified by common name and are organized by the life-form cla~ses described in Appendix 2. Scientific names are listed in Appendix 6. (2) The cover values in the table refer to the canopy cover classes shown in Appendix 2.

39 Objective 4: Identify areas of native vegetation suitable for special management designation, including areas that represent the vegetation types of the Ecosystem and areas with rare or unique vegetation types. A. Representative Areas Several proposed special management areas have been designated in the Jack Morrow Hills Ecosystem (the sand Dunes, Oregon Buttes, and White Mountain Petroglyphs ACECs) or. proposed for the Ecosystem (the steamboat Mountain ACEC, and the Buffalo Hump, sand Dunes, Alkali Draw, oregon Buttes, and Whitehorse Creek .Wilderness Study Areas) (USDI Bureau of Land Management 1992). Unfortunately, because'most of the plant associations on which this project focussed -- the mountain shrub associations - occur as small stands scattered throughout the central part of the Jack Morrow Hills Ecosystem, none of these existing or proposed special management areas includes representative stands of all of the associations. Moreover, no single area was discovered during the extensive survey that contains all of the associations. Bush Rim probably is the site within the Ecosystem that best represents the relationship between the big sagebrush mountain shrub types and the environment, with the large mountain big sagebrush-Utah snowberryjbasin wildrye stand on the escarpment and the smaller basin big sagebrush/basin wildrye and Wyoming big · sagebrush/ western wheatgrass stands at the foot of the escarpment. Other vegetation types that are peripheral to this project but nonetheless are salient parts of the Ecosystem also occur at Bush Rim: a large cushion plant stand on the rim above the escarpment, small stands of Bebb willow around springs at the foot of the escarpment, and Wyoming big sagebrushjbottlebrush squirreltail vegetation and Gardner saltbush vegetation on the valley floor below the escarpment. Three of the plant species of special concern discussed in this report also occur at the foot of the escarpment of Bush Rim: Lesguerella macrocarpa (occurrence #002), Phacelia demissa (occurrence #001), and Phacelia salina (occurrence #003). A small area of the Utah juniperjbluebunch wheatgrass association apparently is included in the White Mountain Petroglyphs ACEC, but this ACEC probably is too small to represent this association. The Utah juniper woodlands around Essex Mountain could be included in the Sand Dunes ACEC if the boundary of that ACEC was extended to include the western part of Township 24 North, Range 103 West (Essex Mountain quad, Appendix 3). The existing ACEC boundary apparently excludes the Utah juniper woodland there (USDI Bureau of Land Management 1992, Map 26).

40 The! proposed Steamboat Mountain ACEC apparently includes patches of the true mountain mahoganyjbluebunch wheatgrass associat[on (USDI Bureau of Land Management 1992, Map 26). This associatlion occurs as small patches, .and the small stands in the proposedJ ACEC seem to represent the type in the Ecosystem. The proposed ACEC also includes some of the larger stands of cushion plant ve~etation noted in the Ecosystem. Designation of any of the special· management areas mentioned above will fail to address the importance that the scattered stands of mountain shrub vegetation hold for the desert elk herd, for mule deer, and probably for other animals in the Ecosystem. These small patches of habitat can be protected from unnecessary disturbance if roads, pipelines, drilling rigs, and other facilities are kept away from the steep slopes and the narrow valley· bottoms in which they occur. The maps in.Appendix 3 will be useful in determining when proposed developments might affect mountain shrub stands. · B. Unique Areas The large stands of the basin big sagebrush/lemon scurfpea association on aeolian sand in the Steamboat Rim area apparently are a unique occurrence: the Wyoming Natural Diversity Database is unaware of other big sagebrush stands.like these in the state, and none have been reported in The Nature Conservancy's . preliminary vegetation classification for the western u.s. (Bourgeron a.nd Engelking 1994). Much of this occurrence is contained in the Sand Dunes ACEC, but the area along the western side of Township 24 North, Range 103 West and along the eastern side of Township 24 North, Range 104 West excluded from the ACEC (USDI Bureau of Land Management 1992, Map 26) may leave out part of.the big sagebrush occurrence. The boundary of this big sagebrush occurrence and the boundary of the AC~C should be compared at _a scale of 1:24,000 to determine if the 1 ACEC is leaving out a significant.part of the occurrence. PLANT SPECIES OF SPECIAL CONCERN

Seven USFWS C2 candidates and Rock Springs BLM spec~al status plant species were targeted for survey in the Jack Morrow Hills Ecosystem in 1995 (Table 8). Surveys also focused on nine WYNDD species of special concern known to occur in the study area (wYNDD records) • In all, ten species of concern were documented in the Jack Morrow Hills area in 1995, including_four species not previously known from the ecosystem. Six other species of concern are known from the area based on recent or historical herbarium specimens (RM, WYNDD records). In all, sixteen plant species of special concern are now confirmed from the study area (Table 9). Information on the identification, biology, status, and threats 41 for each of these species is summarized in the following section.

Of the seven target USFWS C2 species, three were found during 1995 surveys (Antennaria arcuata, Lesguerella paysonii, and oryzopsis contracta). Potential habitat was investigated for the remaining four species, but no populations could be located. Survey results for these plants are summarized below: 1) Artemisia biennis var. diffusa (Mystery wormwood): This taxon is known from a single record on clay flats and playas in the vicinity of Jim Bridger Power Plant, north of Point of Rocks, Wyoming. The type location was searched in late July 1995, but no individuals could be found. Potential dry lake and playa habitats.were investigated in the Greasewood Draw and Jack Morrow Creek watersheds and in the vicinity of Honeycomb Buttes within the study area, but no plants could be found. Although it is possible that this biennial may not appear every year (persisting in a seed bank during drought years), the unusually wet conditions of 1995 would seem to have been favorable for seedling establishment. Follow-up surveys should be conducted in suitable habitats in 1996 to determine if second-year plants may have arisen from undetected seedlings produced in 1995. Repeated searches in the Point of Rocks area during the last 15 years have failed to relocate this taxon, and it is possible that it may be extinct. Questions have also been raised about the validity of the taxon, but critical studies have been hampered by the lack of additional specimens. 2) Cirsium aridum (Cedar Rim thistle): Fertig (1995 c) reported a single occurrence of Cedar Rim thistle from a ridge less than 1 mile east of Freighter Gap within the Jack Morrow Hills Ecosystem. In the spring of 1995, R. Dorn and w. Fertig reexamined all reported specimens of ~. aridum and ~- pulcherrimum in the RM collection to determine if additional morphological characteristics could be found to reliably distinguish these two closely related species. As a result of this analysis, the Freighter Gap population was determined to be a pubescent form of c. pulcherrimum rather than c. aridum (Fertig 1995 d). Although typically. glabrous, populations of ~- pulcherrimum in central Wyoming may have white-hairy upper leaf .surfaces closely resembling ~. aridum (Fertig et al. 1994). Pubescent forms of~. pulcherrimum can be differentiated from c. aridum by typically having more than 4 heads in an elongate inflorescence, bright green surfaces beneath the white pubescence on the upper leaf su~faces, taller stems with thickened bases, unbranched rootstalks and yellow-rimmed fruits (Fertig 1995 c, 1995 d). Potential~- aridum habitat on barren, chalky-sandstone or clay slopes, fans, and draws was investigated in the White Mountain and Steamboat

42 Mount~in areas in 1995, but only c. pulcherrimum could be loc:ated. As a result of surveys in 1994-95, i~ appears unlikely that c. aridum occurs in th~/Jack Morrow Hills Ecosystem.· 3) Phlox opalensis (Opal phlox): A small population of large..;.flowered, mat-forming phloxes was discovered on.· Pacific Butte, north of oregon Butte~, in June,· 1995. · initially, it was suspected that these plants might . represent a disjunct occurrence of P. opalensisl a rare, regional endemic of the lower Green.River and Bridger basins of southwestern Wyoming and adjacent Utah (Fertig 1996 c). This species can be recognized by its large flowers (typically over 15 mm wide when fresh), narrow leaves, and elongated hyaline internodes (Dorn 1992; Fertig et al. 1994). When compared with authenticated ~aterial, however, it was found that the Pacific Butte phloxes merely represented large-flowered forms of I!~ hoodii, a common species found throughout the state. No other. potential ,1!. opalensis populations nor suitable habitat were. found in the Jack Morrow Hills Ecosystem in 1995. 4) Thelesperma caespitosum (Green River greenthread): Potential barren shale habitat for this species was investigated along the north end of White Mountain within the study area in 1994 and 1995, but no populations could be located. At present, ~. caespitosUm is known in Wyoming from only two small occurrences on sparsely vegetated ridgetops of gravelly white shale~sandstone ash in the vicinity of the city of Green River (Fertig 1995 a)~ It appears unlikely that this species will be found in·the Jack Morrow Hills area, although potential unsurveyed habitat may be found in the Leucite Hills, south of the ecosystem boundary.

f 43 Table 8. Target, Plant Species for survey in the Jack Morrow --- Hills Ecosystem.

Species/English Name Heritage YYNDD Range USFYS ' Other Federal Rank List Status Status Antennaria arcuata G2/S2 GR R * SS-Rock Springs BLM Meadow pussytoes Artemisia biennis var. diffusa G5T1Q/S1 GR E * ss~Rock Springs BLM Mystery wormwood Cirsiun aridun G2/S2 GR E * SS-Rock Springs BLM Cedar Rim thistle Lesguerella macrocarpa G2/S2 GR E * SS-Rock Springs BLM Large-fruited bladderpod Oryzopsis contracts G3/S3 R * SS•Rock Springs BLM Contracted Indian ricegrass Phlox opalensis G3/S3 LD R * SS~Rock Springs BLM Opal phlox Thelesperma caespitosun G1/S1 GR R * SS-Rock Springs BLM Green River greenthread

* Formerly designated as a c~tegory 2 (C2) c~ndidate by. the us Fish and Wildlife Service. In July, 1995, USFWS revised its candidate system and eliminated the C2 designation. Oryzopsis contracta had previously been recommended for downgrading to 3C status by Fertig (1994). · Codes: Heritage Rank; G = global rank, s = state rank. WYNDD List; GR = globally rar~, LD = limited distribution, SR = state rare Range; R = regional endemic, E = state endemic, P = peripheral. Codes from Fertig 1996 a.

44 Table 9. Plant Species of Special Concern of the Jack Morrow Hills Ecosystem.

Species/English Name Heritage WYNDD Range USFYS Other Federal Rank List Status Status Antennaria arcuate G2/S2 GR R * SS-Rock Springs BLM Meadow pussyti:les

Astragalus nelsonianus G3/S2 LD R Nelson's milkvetch ~- pectinatus var. Dlatyphyllus] Carex parryana var. parryana G4G4/S1 SR p Parry sedge

Cryptantha scoparia G3/S1 SR R Desert cryptantha Eriastrum wilcoxii G5/S1 SR p Yilcox eriastrum

Erigeron uintahensis G4/S1 SR R Uintah fleabane [~. spec_iosus var. uintahensis]' Eriogonum divaricatum G4G5/S1 SR p Divergent .wild buckwheat

Ipomopsis crebrifolia G3/S2 LD R C~ct gilia Lesguerella macrocarpa G2/S2 GR E * SS-Rock Springs BLM Large-fruited bladderpod Monolepis pusilla G5/S1 SR p Red poverty-weed Oryzopsis contracts G3/S3 R * SS-Rock Springs BLM Contracted Indian ricegrass oxytheca dendroidea G4/SH SR p ·Tree-Like oxytheca

Penstemon paysoniorum G3/S3 E Payson beardtongue Phacelia demissa G5/S1 SR p Intermountain phacelia Phacel ia salina G3Q/S1 SR p Nelson phai:elia Phacelia scopulina var. scopulina G4/S1 p Prostrate phacelia

* Formerly designated as a Category 2 (C2) candidates by the us Fish and Wildlife Service. In July, 1995, USFWS revised its candidate system and eli~inated the C2 designation. Oryzopsis contracta had previously been recommended for downgrading to 3C status by Fertig (1994). Codes defined inTable 8.

45 Antennaria arcuata Cronq. Meadow pussytoes Asteraceae or Compositae (Sunflower Family)

Legal Status: Rock Springs BLM: Special Status plant~ USFWS: None (formerly C2). Heritage Rank: G2/S2 (WYNDD Global Rare list). Description: Meadow pussytoes is a white-woolly perennial herb that spreads by conspicuously arching woolly stolons up to 10 em long (Figure 3). Flowering stems are 30-40 em tall with relatively few oblanceolate leaves that are equally grayish-white hairy above and below. Flower heads are numerous, clustered at the tip of the stem, and have membranous, white-tipped bracts and white disk flowers (ray flowers are absent). Individual plants are ~nisexual. Pistillate plants have involucres 4-6 mm long and staminate plants have involucres 5-7 mm long (Cronquist 1950~ Dorn 1980~ Marriott 1986~ Fertig et al. 1994~ Fertig 1996 b). Similar Species: Antennaria microphylla, A· parvifolia, A· rosea, and A~ umbrinella have short, non-woolly stolons and densely crowded basal rosettes. A· flaqellaris has slender, glabrous stolons and inflorescences composed of a single flower_head. Other Antennaria species in Wyoming lack stolons, have glabrous upper· leaf surfaces, or dark-tipped involucre bracts. Gnaphalium chilense is an annual or biennial herb with bisexual flower heads and yellowish, membranous involucre bracts (Dorn 1992; Fertig et al. 1994). Geographic Distribution: Regional endemic of northeastern · Nevada, south-central Idaho, and central Wyoming. In Wyoming, it is known only from the Sweetwater River Valley in the vicinity of Atlantic City and Jeffrey City in Fremont County (:Fertig et al. 1994). Occurrences Within the Study Area: A single population was discovered in the Oregon Gulch drainage, approximately 4 miles west of Continental Peak, by Laura Welp of the Rocky Mountain Herbarium in 1995. Surveys in other areas of potential habitat along Dickie Springs in 1995 were unsuccessful. All other Wyoming occurrences of this species are found to the northeast.of the Jack Morrow Ecosystem boundary (Fertig 1996 b). Habitat: Occurs in moist, often hu.mniocky, subirrigated meadows, seeps, or springs dominated by Deschampsia cespitosa and Juncus balticus var. montanus. Occasionally, populations 46 can also be found bordering shrublands of Artemisia cana var. cana and Pentaphylloides floribunda (Marriott 1986; Fertig 1996 b). Plants are often found on neutral to basic soils high in organic matter, calcium, magnesium, and sodium (Bayer 1992). Flowering/Fruiting Period: July-September. Population Size and Condition: Census data are not available for the oregon Gulch population. Elsewhere in Wyoming, populations average 3000-5000 individuals. (Fertig 1996 b). Existing and Potential Threats: Grazing by livestock has been considered the main threat to this species (Marriott 1986). Exclosure studies, however, ·show that populations that are not grazed have difficulty maintaining themselves in dense graminoid vegetation. Ungrazed sites also tend to retain greater moisture that favors other competing species. Trampling by livestock remains a. threat, however. Mining, water diversions, .and trampling. by vehicles are additiona! potential threats (Fertig 1996 b).

47 Figure 3. Antennaria arcuata. Illustration from Fertig et al. 1994.

-- ---~---~------~------

Flower heads numerous; involucre ~ 4-6 mm long in pistillate plants, 5- 7 mm long in staminate plants, bracts membranous, white-tipped; disk flowers white

Loosely white woolly perennial herb, 30-40 em tall Basal leaves few, oblanceolate, f- equally grayish-white hairy above and below; stem leaves narrow

Ill. by W. Fertig Arching, woolly stolons to 10 em long

48 Astragalus nelsonianus Barneby Nelson's milkvetch Fabaceae or Leguminosae (Pea Family)

Synonym: A. pectinatus (Hook.) Dougl. ex G. Don var. platyphyllus Jones. Legal Status: None. Heritage Rank: G3/S2 (WYNDD Limited Distribution list). Description: Nelson's milkvetch is a selenium-scented perennial herb with fleshy-leathery stems 10-30 em tall (Figure 4). Stems are decumbent at the base and arise from a shallowly . buried rootcrown. · Lower stipules are papery and fused, while the upper stipules may be free or fused only at the base. Leaves are 4-9 em long, nearly sessile, and divided into 5-11 linear to oblong leaflets. The leaflets are equally pubescent above and below with short, appressed, basally-attached hairs. Individual leaflets are attached directly to the grooved rachis without a distinct joint. The inflorescence is a raceme of 6-20 white flowers with banners over 20 mm long. The calyx .tube is 7-9 mm long. Fruits are oblong to elliptical, 15-33 mm long, semi-woody at maturity, and borne on downward-curved stalks (Barneby 1964, 1989; Dorn 1992). Similar Species: Astragalus grayi has erect to ascending fruits, calyx tubes shorter than 6 mm, and cream-colored flowers. A· pectinatus has smaller fruits and extremely narrow leaflets with strongly inrolled margins. A· bisulcatus often has purple or bicolored flowers, leaflets jointed to the rachis, and 2-grooved fruit (Dorn 1992). Geographic Distribution: A· nelsonianus is a regional endemic of southwestern Wyoming and adjacent northeastern utah and northwestern Colorado (Barneby 1989). In Wyoming it is known from the Rock Springs Uplift and Green River, Great Divide, and Wind River basins (Fremont, Natrona, and Sweetwater counties). Occurrences Within the Study Area: Nelson's milkvetch is known from four occurrences within or just south of the Jack Morrow Hills Ecosys~em boundary. Populations near Black Rock, Split Rock Canyon (NW of steamboat Mountain), and Bush Rim were all observed between 1973 and 1980. One new population was discovered during 1995 surveys along Greasewood Wash, north of Black Rock. ·

49 Habitat: Occurs on alkaline, often seleniferous, clay flats, shale bluffs and gullies, pebbly slopes, and volcanic cinders. Known occurrences are typically found in sparsely vegetated sagebrush, juniper, and cushion plant communities. The population from Greasewood Wash is found in an Artemisia tridentata var. wyomingensis-Chrysothamnus viscidiflorus community on a stabilized sand dune covered with fine reddish gravel. Flowering/Fruiting Period: Mid May-late Junejlate June-August. Population Size and Condition: The Greasewood Wash population was observed to be small with widely scattered individuals in 1995. Census data are lacking for the other occurrences in the Ecosystem. Existing and Potential Threats: This species could be potentially impacted by trampling from off-road vehicles or road construction associated with mineral development. Additional Comments: Darn (1992) emphasizes differences·in the pubescence of the upper leaflets in distinguishing A. nelsonianus (~. pectinatus var. platyphyllus) from A. pectinatus var. pectinatus. Typical specimens of ~ nelsonianus are equally pubescent on both sides of the lea+lets, but rare individuals (including some plants from Greasewood Wash) may be glabrate.

50 Figure 4. Astragalus nelsonianus. Illustration from Barneby 1989.

Astragalus nelsonianus

51 Carex parryana Dewey var. parrvana _ Parry sedge Cyperaceae (Sedge Family)

Legal Status: None.

Herit~ge Rank: G3G4/S1 (WYNDD State Ra-re list) • Description: Parry sedge is a loosely tufted perennial with short, creeping rhizomes (Figure 5). stems are 20-40 em tall, erect, and exceed the basal leaves. Leaves are flat, 2-4 mm wide, and in clusters of 5-12 near the base of the stem. The inflorescence consists of 3-6 elongate spikes that are not obviously clustered, at least at the base. The terminal spike consists of either all staminate flowers or both pistillate and staminate (with the staminate located at the base). Lateral spikes consist only of pistillate flowers, and at least one spike is typically as large as the terminal spike. The lowest spike is subtended by a short, nearly sheathless bract. Perigynia are 2.5 mm long, brown, rounded at the tip and minutely toothed along the margins. The beak of the perigynium is 0.1-0.6 mm long and either ·entire or 2-toothed-. Pistillate scales are dark reddish brown with a green midrib and white membranous margins and typically equal the perigynia in size. Achenes are three sided and short-stalked at the base. Pistillate flowers have 3 stigmas (Murray 1969; Hermann 1970; Cronquist et al. 1977; Dorn 1992). Similar Species: Carex parryana var. unica has lateral spikes shorter than the terminal spike and often confluent into an elongate, 11 single-headed11 inflorescence. Other sedge species with 3 stigmas differ in having glabrous perigynia, dark pistillate scales, or spikes aggregated into a single head (Murray 1969; Dorn 1992). Geographic Distribution: Occurs from central Manitoba to southern Alaska, south to Utah and northern Colorado (Murray 1969). In Wyoming, Parry's sedge is known from the Black Hills, sweetwater River Valley, and Green and Great Divide basins in Carbon, Crook, and Sweetwater counties. Occurrences Within the study Area: Two historical records are known from wetland areas within the Jack Morrow Hills Ecosystem. The oldest dates from 1901 and was collected near a spring along 11 Jackamore Creek11 , which may have been an old name for Jack Morrow Creek. Isolated springs in the vicinity may still provide habitat, although no specimens of 52 Parry sedge were located in 1995 surveys. A second record dating from 1973 is found along Black Rock Wash. Habitat: Parry's sedge is found in wet meadows, swales, and moist low ground in prairies and high plains (Cronquist et al. 1977). Flowering/Fruiting Period: June-July. Population Size and Condition: Not known. The "Jackamore creek" population may not be extant. Existing and Potential Threats: Development of wetland areas, water diversion, trampling by vehicles, and heavy grazing are potential threats to this species. Additional Comments: Parry's sedge is reported to be "rare to infrequent and very local" throughout its range (Hermann 1970).

53 Figure 5. Carex parryana var. parryana. Illustration from Hermann 1970.

54 Crvctantha scoparia A. Nels. Desert cryptantna Boraginaceae (Borage Family)

Legal Status: ·None. Heritage.Rank: G3/S1 (WYNDD State Rare list). Description: Desert cryptantha is a slender, multi-branched, annual herb with stems 5-30 em tall (Figure 6). The stems and leaves have short, appressed to spreading hairs, with those of the leaves often having enlarged, wart-like bases. Leaves are linear, alternate, 1-4 em long and 1-3 mm wide. The leafless flower spikes are elongate, 2-15 em at maturity, and often paired at the tips of branches. In fruit, the calyx is narrow, 4-6 mm long, and densely pubescent with a mix of closely ascending hairs and stiff, spreading bristles. The corolla is white, about 1 mm wide, and barely exceeds the calyx in length. Each fruit is composed of four, equal-sized, lance-shaped nutlets, 0.5-0.7 mm wide, and covered with tiny, upward-pointing, curved · spines (Hitchcock et al. 1959; Cronquist et al. 1984; Darn 1992). Similar Species: Cryptantha kelseyana has nutlets of two size classes within the same blossom. c. fendleri has smooth nutlets. g. ambigua has wider, more oval nutlets covered by rounded tubercles (Darn 1992). Geographic Distribution: g. scoparia occurs from eastern Washington and Oregon to northern Nevada, south-central Montana, northern Utah, and southwestern Wyoming (Cronquist et al. 1984; Lesica and Stickney 1994). In Wyoming, it is known from the Green River .and Great Divide basins in Lincoln, Sublette, and Sweetwater counties. Occurrences Within the Study Area: A single record of this species (last observed in 1981) is known from the vicinity of Oregon Buttes. Habitat: Occurs on dry, open flats and slopes, typically among sagebrush (Cronquist et al. 1984). Wyoming populations have been reported from sandy, clay, or gravelly slopes, flats, and rims (WYNDD records). Flowering/Fruiting Period: May-June/June-July. Population Size and Condition: Census data are lacking for the Oregon Buttes occurrence. 55 Existing and Potential Threats: Not known. Additional Comments: This species is easily overlooked and may be more abundant in Wyoming and adjacent states than existing herbarium records indicate. Surveys in the Green River Bas~n by Tom Cramer and Charmaine Refsdal of the University of Wyoming and Walter Fertig resulted in the discovery of seven new occurrences for the state in 1995.

Figure 6. Cryptantha scoparia. Illustration from Cronquist et al. 1984.

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Cryptantha scoparia

56 Eriastrum wilcoxii (A. Nels.) Mason Wilcox eriastrum Polemoniaceae (Phlox Family')

Synonym: E. sparsiflorum (Eastw.) H. Mason var. wilcoxii (A. Nels.) cronq. Legal status: None. Heritage Rank: G5/S1 (WYNDD State Rare list). Description: Wilcox eriastrum is a slender, often woolly pubescent, annual herb with erect, multi-branched stems 10- 30 em tall (Figure 7). The leaves are alternate, 1-3 em long and pinnately divided into 1-3 pairs of spiny-tipp~d leaflets. Flowers·are clustered in densely woolly-hairy, compact heads surrounded by spiny, pinnately compound bracts. Lobes of the calyx are spiny and strongly unequal in length. The corolla is pale blue, lavender, or white with a yellow throat and barely exceeds the calyx. Anthers are arrow-head shaped and over 0.7 mm long (Harrison 1972; Cronquist et al. 1984). Similar Species: ,Navarretia intertexta has anthers less than 0.5 mm long, more pronounced inflorescence bracts, and glabrous or'hairy (but not woolly-.hairy) flower heads. Ipomopsis pumila has calyx lobes that are equal .in size and an inflorescence with broad,·glassy hairs. Geographic Distribution: Wilcox eriastrum occurs from central Washington south to Nevada and southern California and east to southwest Wyoming and western Utah (Cronquist et al. 1984). In Wyoming, it is known.from the Wind River and Green River basins in Fremont and Sweetwater counties. Occurrences Within the study Area: One recent collection is known from the Jack Morrow Hills Ecosystem in the Eden Valley. A second record is known from the west side of Wyoming Highway 191, just outside of the ecosystem boundary. Additional habitat may be present in stabilized sand dune areas on. the edges of the Killpecker Dunes. Habitat: Dry, open sandy hills and flats in desert areas (Cronquist et al. 1984; Darn 1992). Populations in and near the Jack Morrow Hills Ecosystem are found in sandy Artemisia-Chrysothamnus communities. · Flowering/Fruiting Period: May-early September.

57 PopulationSize and Condition: No census data are available for the Eden· valley occurrence, but other populations in the state have been observed to be locally common within suitable microenvironments·. Existing and Potential Threats.: Trampling or soil erosion resulting from off-road vehicle activity in stabilized dune areas are potential threats.

Figure 7. E:tiastrum wilcoxii. Illustration from Harrison 1972.

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·------~

58 Erigeron uintahensis Cronquist Uintah fleabane Asteraceae or Compositae (Sunflower Family)

Synonym: E. speciosus (Lindl.) DC. var. uintahensis (Cronq.) . Welsh. Legal Status: None. Heritage Rank: G4/S1 (WYNDD state Rare list).

Description: Uintah fleabane is a perennial herb wi~h a woody rootstalk or stout rhizome (Figure 8). Stems are erect, leafy, and have a mix of short, glandular hairs (especially on the upper stem) and long, multi-celled nonglandular hairs. The leaves are entire with ciliate margins and a mix of glandular and nonglandular hairs. Basal and lower stem leaves are oblanceqlate, 4~10 em long, 6-18 nun .wide, and have fewer glandular hairs. Mid and upper stem leaves are about equal in size to the lower leaves, but are sessile, oval to lance-shaped, and more obviously glandular. The inflorescence is co~posed of 1-5 flower heads with glandular involucres 5.5-7 mm long and disks 12-18 mm wide. Ray flowers are blue or rose-purple, 9-15 nun long, about 1 nun wide, and number 75-125 per head. The pappus consists of 2 unequal sets of smooth bristles. Fruits are hairy achenes (Cronquist 1947, 1994; Welsh 1983; Dorn 1992). Similar Species: Erigeron speciosus and E. subtrinervis lack glandular hairs on the le~ves or stems. ~. formosissimus has upper stem leaves that are conspicuously smaller than the lower leaves. ~. peregrinus has less numerous and wider (over 1.5 nun) ray flowers (Welsh 1983; Dorn 1992). Geographic Distribution: Uintah fleabane is a regional endemic of northeastern and central Utah and southern Wyoming (Welsh et al. 1993). In Wyoming, it is known only from the Rock Springs Uplift, Uinta Mountains, northern Laramie Range, and the rim of the Gr~at Divide Basin (Albany, Sweetwater, and Uinta counties). Occurrences Within the Study Area: A single, small occurrence was found in Box Canyon on Steamboat Mountain d~ring ecological surveys in 1995. Habitat: This species may ·be found in sagebrush slopes or meadows, and aspen, lodgepole pine or spruce-fir forests from the foothills to the alpine zone (Welsh et al. 1993). On steamboat Mountain, it is found in an Artemisia 59 tridentata var. vaseyana tall shrub community with a dense 4 ' understory of Symphoricarpos oreophilus, Purshia tridentata, and mid-sized forbs.

Flowering/Fruiting Period: Late June-early September~ Population Size and Condition: The population on steamboat Mountain is extremely small and contributes less than 1% of total cover. Population data are lacking for other Wyoming occurrences. Existing and Potential Threats: Not known. Additional Comments: Welsh (1983) considers this species to be a variety of E. speciosus due to intergradation of specimens of the two taxa in Utah. Cronquist (1994) also notes "puzzling intergrades" but maintains E. uintahensis as a separate species. Some Wyoming specimens, including the material from Steamboat Mountain, differ in pubescence characters from "typical" Uinta Mountain plants. This· species is relatively abundant in the Uinta Mountains of northeastern Utah, but is known from only 7-8 extant populations in Wyoming. Add~tional field studies in southwestern Wyoming may show that Uinta fleabane is more widespread than currently .suspected ~nd not in need of. special concern.

60 Figure a. Erigeron uintahensis. Illustration from Cronquist 1994.

2/5

Erigeron uintahensis

61 Eriogonum divaricatum Hook. Divergent wild buckwheat Polygonaceae (Buckwheat Family)

Legal Status: None. Heritage Rank: G4G5/S1 (WYNDD State Rare list). Description: Divergent wild buckwheat is a low, spreading annual with stems 5-20 em high (Figure 9). Basal leaf blades are oblong to oval, 1-2 em wide, and green above and crinkly pubescent beneath. Stem leaves are similar to the basal leaves, but become gradually reduced in size. Flowering stems are somewhat dichotomously branched, pubescent, and leafy. Involucres are 1-2 mm long, top-shaped, pubescent, and 5-lobed. The flowers are yellowish, 1.5-2 mm long, and glandular hairy on the outside. Achenes are light brown and 1.5-2 mm long (Reveal 1969; Welsh et al. 1993). Similar Species: All other annual Eriogonum species in southwestern Wyoming have glabrous flowers or lack developed stem leaves (Darn 1992). Geographic Distribution: E. divaricatum occurs from southwestern Wyoming to southeastern Nevada, Arizona, and New Mexico (Reveal 1969). In Wyoming, it is restricted to the Green River and Great Divide basins in Sublette, sweetwater, and Uinta counties. Occurrences Within the Study Area: In 1995, one population was located on the north rim of Alkali Draw, 4.5 miles east of Bush Rim. This discovery represents the first record of this species in the Jack Morrow Hills Ecosystem and the first confirmed report for sweetwater County in the last half-century (WYNDD records). Habitat: In Wyoming, this species is typically found on clay flats and slopes dominated by Atriplex qardneri. The Alkali Draw population occurs in a sparsely-vegetated Atriplex gardneri-Artemisia pedatifida community on a mesa top of fine-textured brownish clay-shale with a surface layer of gravel. Flowering/Fruiting Period: July-September. Population Size and Condition: The Alkali Draw occurrence contains an estimated 5000 plants in an area of less than 1 acre. The same area also has a large population of Phacelia ) demissa, another Wyoming species of special concern. 62 Existing and Potential Threats: -No threats are known. The habitat .of the Alkali Draw pop~lation is sufficiently isolated by physical barriers to protect it from most threats. Figure 9. Erioqonum divaricatum. Illustration by Walter Fertig.

·(

63 Ipomopsis crebrifolia (Nutt.) Dorn Compact gilia Polemoniaceae (Phlox Family)

Synonym: I· congesta var. crebrifolia; Gilia congesta var. crebrifolia. Legal Status: None. Heritage Rank: G3/S2 (WYNDD Limited Distribution list). Description: Compact gilia is a perennial herb with unbranched, low, matted stems 3-12 em tall (Figure 10). Leaves are crowded in a basal rosette and scattered along the erect flowering stems. The leaves are linear, mostly glabrous, unlobed, and 1-2.5 em long. Flowers are crowded in a terminal, rounded head-like inflorescence beset with short hairs. ·The corolla is white with a 3-5 mm long tube and 5 spreading, elliptic lobes 1.5-3 mm long. stamen filaments are longer than the anthers. The fruit is a capsule 2.5-4 mm long (Cronquist et al. 1984; Dorn 1992). Similar Species: Ipomopsis congesta var. congesta has whitish grey pubescent, pinnately compound leaves and heads with long, tangled hairs. I. spicata has an elongate (often drooping) inflorescence and pubescent, pinnately divided leaves (Dorn 1992). Geographic Distribution: I. crebrifolia is a regional endemic of southwestern Montana, western Wyoming, western Utah, and northern New Mexico (Cronquist et al. 1984). Welsh et al. (1993) suggest that plants from southwestern Utah may be transitional to I· congesta var. congesta and may possibly be of independent origin. In Wyoming, the species is found in the Great Divide and Green River basins and in the foothills of the Wind River and Wyoming ranges in Fremont, Lincoln, Sublette, Sweetwater, and Teton counties (WYNDD records). Occurrences Within the Study Area: This species is known from 5 locations within the Jack Morrow Hills Ecosystem and several additional occurrences just west of ~he ecosystem boundary. Two populations were located along the north end of White Mountain in 1995. Other occurrences on the north and east slopes of Oregon Buttes, Mowing Machine Draw,. and Steamboat Mountain were last observed in 1994 (Welp et al. 1995; WYNDD records) .

. ) 64 Habitat: Found on barren or semi-barren clay, shale, or sandstone· slopes in cushion plant-bunchgrass communities or on the fringes of sagebrush grasslands.

Flowering/Fruiting Period·: Late May-early ~unejlate June-August.

Population Size and Condition: Census dat~ are available for only three of the known. oc.currences within the ecosystem. Populations range in size f.rom 50 to over 2000 individuals, often restricted to small patches of suitabl.e habitat. Additional unsurveyed habitat is present in upland areas throughout the· ecosystem, however,. and current population estimates are probably conservative. Existing and Potential Threats: Road or pipeline construction through areas of occupied habitat is the main potential threat to this species. Additional Comments: Compact gilia is currently known from 20 occurrences in Wyoming. ·Nine of these have been discovered since 1992. Additional fi~ldwork may prove that this species is more·widespread in the state than currently suspected. Figure 10. Ipomopsis crebrifolia. Illustration from Cronquist et al. 1984. · _.,.;.

Lesguerella macrocarpa A. Nelson · Large-fruited bladderpod Brassicaceae or Cruciferae (Mustard Family)

Legal status: Rock Springs BLM: Special Status plant; USFWS: None (formerly C2). Heritage Rank: G2/S2 (WYNDD Globally Rare list). Description: Large-fruited bladderpod is a densely silvery-grey pubescent perennial (biennial) herb with decumbent stems 5- 3;0 em long (Figure 11). The. basal leaf blades are oval to oblanceolate, 0.5-3 em long, 3-20 mm wide, and petioled. Stem leaves are narrower and stalkless. Flowers have 4 yellow petals 4-7 mm long. · The inflated, globose fruits are 4-8 mm long and borne on recurved stalks. The fruits are slightly hairy on the outer wall and glabrous on the inner surface. Styles are 2-3 mm long (Ro1lins and Shaw 1973; Darn 1980; Fer~ig et al. 1994; Fertig 1995 b). Similar Species: Lesguerella fremontii has smaller fruits that are slightly flattened and densely pubescent on the outer walls and lightly hairy on the inner walls. Other Lesguerella species in Wyoming have linear leaves or fruits borne on ascending or S-shaped fruitstalks. Physaria species have inflated fruits that are notched at the.top (Fertig et al. 1994). Geographic Distribution: L. macrocarpa is endemic to.the western rim of the Great Divide Basin (Sweetwater and Fremont counties) and the Green River Basin near Opal (Lincoln County) and Ross Butte (Sublette County) (Fertig 1995 b; Cramer and Hartman 1995). Occurrences Within the Study Area: Six (.)f the nine confirmed or reported occurrences of large-fruited bladderpod worldwide are found within the Jack Morrow Ecosystem. The extensive population along Bush Rim wa~ resurveyed in 1995, but two reported occurrences in the Blind Canyon and Continental Peak areas could not be found for the second straight year (Fertig 1995 b) • An ambiguous loc.ation reported for the east side of Alkali Draw was relocated 2.25 miles south of Bush Rim in 1995 (Occurrence# 007). Habitat: This species occurs in sparsely-vegetated Atriplex gardneri-Elymus elymoides communities on barren, fine textured bentonitic clays and shales. Populations are usually found on low hills, knolls and colluvial fans below larger ridges (Darn 1980; Fertig 1995 b).

6.6 ~·· Flowering/Fruiting Period: May~JunejMay~July (Fertig 1995 b). Population Size and Condition: In 1994, the population size of L. macrocarpa in the Jack Morrow Hills area was estimated at approximately 52,000 individuals (Fertig 1995 b). Nearly all ·Of these plants were second-year flowering or fruiting individuals (due to drought conditions, first-year seedlings were extremely rare). Follow-up surveys in 1995 found only one flowering plant and no fruiting individuals along Bush Rim. Tens of thousands of first-year seedlings were · encountered, however, at a density of nearly 4 plants per square meter. 1995 Census data from a permanent monitoring plot along Bush Rim are summarized in Tables 10 and 11. Approximately 10,000 first-year plants.were also found in the population near the head of Alkali Draw in 1995 (Occurrence #.007). · Existing and Potential Threats: Trampling by off-road vehicles and other surface disturbing activities (such as road construction) appear to be the main threats to this.species (Fertig 1995 b). These threats are probably most significant during drought years when populations may be at nat~rally low levels and stresses are high. Maintenance of a seed bank is likely to be critical to the long-term survival of the plant at a given site. Imp~cts from wild horses and livestock appear to be less significant than once suspected (Fertig 1995 b). Additional comments: .The dramatic fluctuation in population size and structure observed.between 1994 and 1995 is probably a natural phenomenon dictated by short-term climate changes. The high number of secqnd-year flowering and fruiting plants observed in 1994 may have been the result of favorable seedling establishment in the moist spring of 1993. Drought conditions in 1994, in contrast, resulted in·negligible seedling establishment. As a consequence, few to no second year plants were present in 1995. High seed production in 1994, coupled with favorable spring moisture conditions, probably resulted in the high numbers of seedlings observed in 1995. Regardless of moisture conditions, it is likely that a high number of second-year reproductive plants will be present in the spring of 1996.

67 Figure 11. Lesguerella macrocarpa. Illustration from Fertig et al. 1994 (original from Dorn 1980).

Flowers with 4 yellow Fruits inflated, globe petals, 4-7 mm long shaped, 4-8 mm long, _....--- slightly hairy on outer ~ wall, glabrous on inner wall; fruit stalks recurved

Basal leaf blades oval to oblanceolate, 0.5-3 em long, 3-20 mm wide, petioled; stem Densely silvery-g!ay leaves narrower, sessile pubescent perenmar herb; stems decumbent, 5-30 em long

68 Table 10. Lesquerella macrocarpa Transect # 3 Census Data.

Date: 28 July 1995 Surveyor: Walter Fertig

Subdiv. # Total #S #N #R #D # Fl/Fr branches

1 0 0 0 0 o. 0 2 0 0 0 0 ,0 0 3 11 11 0 0 0 0 4 0 0 0 0 0 0 5 0 0 0 0 0 0

6 0 0 0 . 0 0 0 7 1 1 0 0 0 0 8 14 14 0 0 0 0 9 7 7 0 0 0 0 10 33 33 0 0 0 0 11 39 39 0 0 0 0 12 0 0 0 0 0 0 13 0 0 0 0 0 0 14 0 0 0 0 0 0 15 2 2 0 0 0 0

16 1 1 0 0 0 0 17 0 0 0 0 0 0 18 2 2 0 0 0 0 19 2 2 0 0 0 0 20 0 0 0 0 0 0

21 0 0 0 0 0 0 22 0 0 0 0 0 0 . 23 2 2 0 0 0 0 24 2 2 0 0 0 0 25 0 0 0 0 0 0

26 1 1 0 0 0 0 27 1 1 0 .0 0 0 28 0 0 0 0 0 0 29 1 1 0 0 0 0 30 0 0 0 0 0 0

Total 119 119 0 0 0 0 Number of plants per sqQare meter: .4.0 Number of flowering/fruiting stems per square meter: o Average number of flowering/fruiting stems per reproductive plant: o

% of plots occ~pied: 50% Codes: s =Seedling (vegetative plantwith less than 6 leaves, presumably a first-year plant}, N =Non-reproducing (vegetative plant with 6 or more leaves, pres~ably a non-reproducing second year plant), R =Reproductive (with flowers and fruits), D = Dead, Fl = Flowering, Fr = Fruiting.

69 Table 11. Lesguerella macrocarpa Transect # 3 Census Data (From Fertig 1995,b). Date: 29 May 1994 Surveyor: Walter Fertig and Jane Struttmann

Subcliv. # Total # s # N # R # D # Fl/Fr branches

1 1 0 1 0 0 0 2 0 0 0 0 0 0 3 3 0 1 2 0 4 4 0 0 0 0 0 0 5 0 0 0 0 0 0

6 0 0 0 0 0 0 7 2 0 2 0 0 0 8 0 0 0 0 0 0 9 0 0 0 0 0 0 10 1 1 0 0 0 0

11 0 0 0 0 0 0 12 0 0 0 0 0 0 13 0 0 0 0 0 0 14 0 0 0 0 0 0 15 0 0 0 0 0 0

16 0 0 0 0 0 0 17 0 0 0 0 0 0 18 3 0 2 1 0 2 19 0 0 0 0 0 0 20 0 0 0 0 0 0

21 0 0 0 0 0 0 22 0 0 0 0 0 0 23 0 0 0 0 0 0 24 0 0 0 0 0 0 25 0 0 0 0 0 0

26 0 0 0 0 0 0 27 0 0 0 0 0 0 28 0 0 0 0 0 0 29 1 0 1 .o 0 0 30 1 1 0 0 0 0

Total 12 2 7 3 0 6

Number of plants per square mete~: 0.40 Number of floweringjfruiting·stems per square meter: 0.20 Average number of flowering/fruiting stems per reproductive plant: 2.0 % of plots occupied: 23.3% Codes: s = Seedling (vegetative plant with less than 6 leaves, presumably a first-year plant), N =Non-reproducing (vegetative plant with 6 or more leaves, presumably a non-reproducing second year plant), R =Reproductive (with flowers and fruits), D = Dead, Fl = Flowering, Fr = Fruiting.

70 Monolepis pusilla Torrey ex Wats. Red poverty-weed. Chenopodiaceae (Goosefoot Family)

Legal Status: None. Heritage Rank: G5/S1 (WYNDD State Rare list). Description: Red poverty-weed is a dichotomously multi- branched, erect annual herb 3-20 em tall (Figure 12). The slender, spreading stems have a mealy, whitish·covering when young, but may become glabrous and strongly reddish with age. Leaves are slender,. entire, blunt-tipped, and 2-12 mm long.. The lowest leaves may be deciduous before or during the flowering period. Flowers are 0.2-0.5 mm· long, and arranged in clusters of 1-5 per leaf axil. The perianth is reduced to 3 short, linear sepals oriented on one side of the laterally flattened fruit. The single seed is about 0.5 mm wide and enclosed by a membranous, reddish-brown, minutely bumpy-warty covering (pericarp) (Standley 1916; Hitchcock and Cronquist 1964; Darn 1992). Similar Species: Monolepis nuttalliana is not dichotomously branched, has larger, lobed leaves, and more than 5 flowers per axil. Annual species of Chenopodium are more obviously white or grey mealy and are not dichotomously branched. Annual species of Euphorbia are typically prostrate and exude milky latex when broken. Geographic Distribution: M. pusilla occurs from southeastern Oregon to eastern California, southern Idaho, southern Wyoming, and Colorado (Hitchcock and Cronquist 1964). In Wyoming, it is kno.wn froD.l the Bighorn, Great Divide, and Green River basins in sweetwater and Washakie counties (WYNDD records). occurrences Within the study Area: A small population was found in a stabilized sand dune along the north side of Chicken Springs Road, near the western edge of the Jack Morrow Ecosystem during 1995 surveys. Thi~ population is the first to be encountered in sweetwater County since 1901. Two historical populations are known from just south of the Jack Morrow area in the vicinity of Point of Rocks and the Leucite Hills. Habitat: Red poverty-weed is typically found in desert valleys on dry, alkaline soils (Hitchcock and Cronquist 1964; Darn 1992). The Chicken Springs Road population was found on a stabilized sand dune dominated by Artemisia tridentata,

\ Chrysothamnus viscidiflorus, and scattered Sarcobatus f/ vermiculatus, with an understory of Atriplex qardneri, Kochia americana, Elymus smithii, and Stipa comata. The site was remarkable in the high conc~ntration of annual herb species.

Flowering/Fruiting Period: June~August. Population Size and Condition: Only 9 individuals were observed in a 2 acre area at the Chicken Springs Road site in 1995. Additional habitat is present elsewhere on stabilized dunes on the fringes of the Killpecker Dunes. Existing and Potential Threats: This species could be negatively impacted by trampling or erosion of·stabilized dunes by off road vehicles.

Figure 12. Monolepis pusilla. Illustration from Hitchcock and Cron

-- --~------~-~ 0 16

I ~

Monolepis pusilla

72 Oryzopsis contracta (Johnson) Shechter Contracted Indian ricegrass Poaceae or Gramineae (Grass Family) synonym: o. hymenoides (R. &-s.) Ricker var. contracta Johnson; Achantherum contractum (Johnsc;m) Barkworth. Legal Status: Rock Springs BLM: Special status plant species; USFWS: None (formerly C2, recommended 3C by Fertig, 1994). Heritage Rank: G3/S3 (WYNDD watch list). Description: Contracted Indian ricegrass is a tufted perennial with glabrous stems 25-70 em tall (Figure 13). The leaves areinrolled, 0~5-3 mm wide, and rough-margined. The inflorescence is a long panicle with branches initially contracted but often becoming stiffly spreading at maturity. Spikelets are single-flowered, narrow, and 8-10 mm long. The lemmas are covered by short, white, silky hairs 2-3 mm long (these hairs do not exceed the lemma body in length), and have awns 6-12 mm ~ong (Shechter and Johnson 1966; Fertig 1994; Fertig et al. 19.94) • Similar Species: Oryzopsis hymenoides has a widely spreading, wavy-branched pc:micle and plump lemmas with shorter awns and long, silky hairs that exceed the lemma body in length. o. _micrantha has glabrous lemmas and strictly contracted panicle branches. X Stiporyzopsis bloomeri, an aggregation of sterile hybrids involving o. hymenoides and various species of Stipa, has erect, appressed panicle branches, and more rounded spikelets with distinctly bent awns (Fertig 1994; Fertig et al. 1994). · Geographic Distribution: This species is a regional endemic of western and central Wyoming, southwestern Montana, and north-central Colorado (Fertig 1994). It has also recently been documented in Daggett County, Utah (Charmaine Refsdal, personal communication). In Wyoming, it is known from Albany, Campbell, Carbon, Converse, Fremont, Hot Springs, Natrona, Park, Sublette, sweetwater, Teton, Uinta, and Washakie counties. Occurrences Within the Study Area: Contracted Indian ricegrass is known from 10 occurrences in the Jack Morrow Hills area, 9 of which were relocated or discovered during 1995 surveys. These populations occupy a minimum area of 660 acres. Much additional; unsurveyed habitat occurs on ridges and stabilized sand dunes in the ecosystem.

73 Habitat: Contracted Indian ricegrass is found in basin and foothills areas on sandy or gravelly soils of slopes, rolling plains, and roadsides. It often occurs in communities of Artemisia tridentata var •. wvominqensis/Stipa comata, Artemisia pedatifida/Atriplex qardneri, Sarcobatus vermiculatus, and cushion plant-bunchgrass grasslands with low vegetative cover (Fertig 1994; Fertig et al. 1994). Populations in the Jack Morrow Hills Ecosystem are often associated with shrub and graminoid communities on stabilized sand dunes or gravelly shale-sandstone slopes. Flowering/Fruiting Period: June-August/June-October. Population Size and Condition: o. contracta is usual·ly locally abundant, al: though populations may have a patchy .. distribution pattern. Colonies within the study area range in size from several hundred to over 10,.000 individuals. Given the amount of unsurveyed po~eritial habitat in the ecosystem, the total population may number in the hundreds of thousands. · Existing and Potential Threats: Contracted Indian ricegrass is likely to be a decreaser under destructive grazing practices. Large-scale surface disturbances may also have a negative impact, at leae;t in-the short-term. Surveys of disturbed sites throughout the state, however, have shown that this species is capable of reeolonizing such areas if a refugium of undisturbed habitat or a seed bank are available in the vicinity (Fertig 1994). Overall, the threats to this speeies are low. Additional Comments: Since 1992, over 9o·new occurrences of o. contracta have been documented in Wyoming, Montana, and Utah. This species is closely related to o. hymenoides and may key to it in some floras in which branching characters of the inflorescence are emphasized. The best features to reliably separate the two species are differences in t~e length of lemma hairs and awps of the florets (Fertig 1994). Field surveys in Wyoming in 1993-94 ·found o. contracta to be far more abundant and less threatened than once suspected. Based on these studies, it was recommended for removal from the USFWS candidate list· (Fertig 1994) and has been dropped from the Wyoming plants o'f special conc.ern list by WYNDD (Fertig 1996 a).

74 Figure 13. Oryzopsis contracta. ·Illustration by Isabel Nichols from Fertig 1994.

~-~------~------~------

Int1orescence a panicle, branches initially --- contracted, ...---- . becoming stiffly spreading at maturity

Spikelets single-t1owered, narrow, 8-10 mm long; lemmas slender, covered with silky hairs 2-3 mm long (about equal to lemma in length),,awns 6-12 mm

Leaves inrolled, ~ 0.5-3 mm wide, / rough-margined >;

Trufted perennial; ____.. stems glabrous, ~ 30-70 em tall Ill. by Isobel Nichols

75 --- Oxytheca dendroidea Nutt. ssp. dendroidea Tree-like oxytheca Polygonaceae (Buckwheat Family)

Legal Status: None. Heritage Rank: G4/SH (WYNDD State Rare list). Description: Tree-like oxytheca is an erect, multi-branched annual herb 5-40 em tall and wide (Figure 14). Stems are sparsely to densely glandular and green to reddish purple. Leaves are mostly all basal, linear to oblanceolate, 1-4.5 em long, 0.1-0.7 em wide, and densely pubescent with coarse, stiff hairs. Flowers are in cl-usters of 2-6 within bristle tipped involucres arranged in an open, multi-branched inflorescence. The perianth is 1-2 mm long and composed of 6 white or pink tepals. Fruits are yellow-brown achenes 1-2 mm long (Ertter 1980; Darn 1992). Similar Species: Annual species of Eriogonum and Stenoaonum salsuginosum have involucres without bristle-tips. Geographic Distribution: Subspecies dendroidea occurs from central Washington to east-central California, southern Nevada, southern Idaho, and central Wyoming (Ertter 1980). In Wyoming, it is known only from historical records in the Green River Basin and South Pass area (Fremont, Sweetwater and Sublette counties). An additional, ambiguous record may be from Hot Springs County (Darn 1992). Occurrences Within the Study Area: Tree-like oxytheca is known from a single 1922 collection from the "plains between Eden and Big Piney (near Eden)". This species has not been relocated in the state since that time.

Habitat: 0. dendroidea occurs in dry, sandy to rocky desert habitats, often in association with dunes and dirt roads (Ertter 1980). Flowering/Fruiting Period: June-September. Population Size and Condition: Not ·known. Existing and Potential Threats: May be adversely impacted by trampling and soil erosion.

76 Figure 14. Oxytheca dendroidea. Illustration from Ertter 1980.

(

77 ~. ..

Penstemon paysoniorum Keck Payson's beardtongue Scrophulariaceae (Figwort Family)

Legal Status: USFWS: None (formerly 3C).

Heritage Rank: G3/S3 (WYNDD Watch list)~ Description: Payson's beardtongue is a many-branched, erect, tufted perennial herb with stems 0.8-20 em tall (Figure 15). Leaves are linear to lance-shaped, glabrous, and less than 1 em wide and 6.5 em long. Upper stem leaves may be folded along the midrib and are sessile. The flowers are 15-22 mm long, bright blue, and arranged in a dense, one-sided, glabrous inflorescence. The four pollen-bearing anthers are bluish-black and short-hairy, while the fifth, sterile stamen (staminode) is bearded at the tip (Keck 1947; Cronquist et al. 1984; Jones 1~89). Similar Species: Penstemon fremontii differs in having light gray pube~cence on the leaves and stems. P. strictus has long, tangled hairs on the anthers that equal or exceed the length of each anther sac. P. cyananthus is a taller plant with leaves broader than 1 em (Dorn 1992; Fertig 1993).

Geographic Distribution: The entire global range of ~. paysoniorum is restricted to the' basins of southwestern and central Wyoming (Fremont, Lincoln, Natrona, Sublette, Sweetwater, and Uinta counties). Occurrences Within the Study Area: Two occurrences are known from the oregon Buttes and Rock Cabin Springs areas within the ecosystem. These populations were. last observed in 1980. Habitat: Found in barren hills, sandy creek bottoms, alkaline shale bluffs, and dry hills among sagebrush (Jones 1989). Both known populations in the Jack Morrow Hills area are found on sparsely vegetated ca,lcareous clay-shale slopes ·(WYNDD records). Flowering/Fruiting Period: June-July. Population Size and Condition: Not known·. Existing and Potential Threats: Not known. Additional Comments: P. paysoniorum is known from over 35

78 populations in Wyoming. Recent surveys have found it to be more abundant than once suspected. It has recently been dropped from WYNDD's list of species of special concern (Fertig 1996 a), although it remains of some conservation interest due to its restricted global range.

Figure 15. Penstemon paysoniorum. Illustration from Cronquist et al. 1984.

,~7~-- . _d;L ,«.''n~---· -~"1.5 ~\\'~ \ ~\ staminode 2.5

79 Phacelia demissa Gray -- Intermpunta.j.n phacelia Hydrophyllaceae (Waterleaf Family)

Legal Status: None. Heritage Rank: G5/S1 (WYNDD State Rare list). Description: Intermountain phacelia is an erect, multi-branched annual herb with semi-succulent, brittle, glandular pubescent stems· 3-15 em tall (Figure 16). Leaves are mostly borne on the stems and are short-petioled, although a few long-stalked basal leaves may be present. Leaf blades are oval to nearly round, 1-2.5 em iong, sparsely pubescent, and have entire or slightly wavy margins. Flowers are arranged in short, coiled inflorescences opposite the leaves .or in the fork of stem branches. The calyx is 2-5 mm long at flowering (5-7 mm in fruit) and deeply cleft into 5 linear lobes. Corollas have a yellow tube 5-8 mm long and a 5- lobed lavender to deep purple limb. Styles are 1.5-4 mm long, hairy at the base, and do not extend past the corolla. Ovules number 10-16 per flower~ The fruit is an oblong or roundish, pointed capsule with oblong, pitted seeds 1-1.5 mm long (Howell 1943; Cronquist et al. 1984; Darn 1992). similar.Species: Phacelia salina and P. scopulina have yellow flowers and usually have lobed.or divided leaves. P. incana has corollas 3-4.5 mm long with white to blue lobes. Geographic Distribution: P. demissa ranges from southwestern Wyoming to eastern Utah, southwestern Colorado, and northern Arizona (Cronquist et al. 1984). In Wyoming, it is known only from the Great Divide Basin in Fremont and sweetwater counties. Occurrences Within the Study Area: All four known occurrences of this species in Wyoming are found within the Jack Morrow Hills Ecosystem. Three populations were surveyed in 1995, including two that were not previously known. This species is restricted to the vicinity of Continental Peak, Bush Rim, and Alkali Draw (WYNDD records).

Habitat: Occurs on barren, fine~textured clay~bentonite slopes with low vegetation cover within communities dominated by Atriplex gardneri, Artemisia pedatifida, and Elvmus elymoides. This species is often associated with Lesquerella macrocarpa, another Wyoming plant species of special concern. · ·

80 Flowering'fFruiting'Period: May-la"t:e July. Population Size and Condition: Populations are often locally abundant, although restricted to small areas of suitable habitat. Surveys in 1995 found 7500-14,000 plants in a total area of less than 20 acres. Population size may vary from year to year depending on moisture availability in the growing season. Two of the pop~lations found in 1995 were also visited during the drought year of 1994, but no plants were observed.

Existing and Potential Threats: T~ampling or soil erosion resulting from off~road vehicles is.a potential threat in roadside areas. Otherwise, threats to this species are low. The population on the north side of Alkali Draw is well protected by natural physical barriers. Additional Comments: Plants from Bush Rim were described as a separate species, .(~. knighti), by Aven Nelson in 1901.

Figure 16. Phacelia demissa. Illustration from Cronquist et al. 1984.

Phacelia demissa

81 Phacelia salina (A. Nelson) Howell Nelson phacelia :flydrophyllaceae (Waterleaf Family.)

Synonym: Included in Phacelia lutea var. scopulina by Hitchcock et al. 1959. Legal Status: None. Heritage Rank: G3Q/S1 (WYNDD State Rare list) • · Description: Nelson phacelia is an annual herb with 2-several prostrate or short-ascending, glandular stems 0.5-3 em long (Figure 17). Leaf blades are entire, coarsely-toothed, wavy-margined, or pinnately lobed, 0.5-1.5 em long, and elliptic to oval. The leaves are wedge-shaped at the base with stalks 0.5-3 em long and are finely pubescent with short, stiff hairs. Flowers are often borne near the ground at the base of the stems and are exceeded by the leaves. The.calyx is 2-4 mm long at flowering time (4-6 mm long in .fruit), and approximately equal to the corolla in size. The corolla is bright yellow (although often tinted with lavender), tubular, and 5-lobed •. Stamens are shorter than the corolla tube. Styles are 0.5-1 mm long, and shorter than the calyx lobes (even in fruit). The fruit is a pubescent, pointed capsule 3-4 mm long with 7-10 ovules (Howell 1944; Halse 1981; Dorn 1992). similar Species: Phacelia scopulina has styles 1-2 mm long that typically exceed the calyx in fruit. ,E. demissa has purple white flowers, fewer ovules, and rqunded leaves. P. tetramera has a 4-lobed, white ·or pale yellow corolla less than 2 mm long (Dorn 1992). · Geographic Distribution: P. salinaoccurs from southwestern Wyoming to western Utah and east-central Nevada (Halse 1981). In Wyoming, -it is known from the Green River and Great Divide basins and the foothills of the overthrust Belt and Rock Springs Uplift in Lincoln, Sublette, and Sweetwater counties. Occurrences Within the Study Area: One population, last observed in 1978, is known from the Bush Rim area (WYNDD records). Habitat: Occurs on alkaline flats and clay slopes (Halse 1981). Flowering/Fruiting Period: May-June.

82 Population Size and Condition: Not known. The Bush Rim population could not be relocated in 1994 or 1995. Population numbers may fluctuate yearly depending·on moisture availability. Existing and Potential Threats: Not known. Additional Comments: This species has been considered merely a form of P. scopu1ina with shorter styles (Hitchcock et al. 1959; Cronquist et al. 1984). Ha1se (1981) found the unique characters of P. salina to be sti;ible ·throughout its range and.recommended recognizing the taxon as a full species.

Figure 17. Phacelia salina. Illustration from Cronquist et al. 1984.

-~------/

83 Phacelia scopulina (A. Nelson) Howell var. scopulina Prostrate phacelia Hydrophyllaceae (Waterleaf Family)

synonym: P. lutea var. scopulina. Legal Status: None. Heritage Rank: G4/S2 (WYNDD Watch list). Description: Prostrate phacelia is an annual herb with prostrate or short-ascending, hairy stems 2-10 em long. Leaves are entire, toothed, or shallowly pinnately lobed, 1-3 9m long, short-hairy, and oblanceolate to oblong. Petioles are often as long as, or longer, than the leaf blades. Flowers are borne near the ground at the base of stems and are often concealed by the leaves. The calyx is 2.5-4 mm long at flowering time and 5-8 mm long in fruit. The corolla is 3- 5 mm long, bright yellow (often tinged with purple), pubescent on the outside, and 5-lobed. stamens are shorter than the corolla tube. Styles are 1-2 mm long, pubescent, and exceed the calyx in fruit. The fruit is a hairy, blunt or pointed-tipped capsule 3.5-6 mm long. ovules number 9-15 l per flower. Seeds are 1-2 mm long and corrugated (Howell 1944; Halse 1981; Cronquist et al. 1984; Dorn 1992). Similar Species: Phacelia salina has styles less than 1 mm long and shorter than the calyx in fruit. P. demissa has purple white flowers, fewer ovules, and rounded leaves. ~- . tetramera has a 4-lobed white or pale yellow corolla less than 2 mm long (Dorn 1992).

Geographic Distribution: ~. scooulina occurs from southwestern Wyoming to south-central Oregon, northern Nevada, and western Utah. Disjunct populations are also found in southwestern Montana (Halse 1981). In Wyoming, it occurs in the Great Divide and Green River basins and Rock springs Uplift in Lincoln, Sublette, Sweetwater, and Uinta counties (WYNDD records) • Occurrences Within the Study Area: This species is known from a single small population discovered in 1995 along a ridge paralleling the Tri-Territory Road in the northwestern portion of the ecosystem. Two additional populations are found on White Mountain, just outside of the study area.

84 Habitat: Occurs on.loosely sandy. or gravelly soils and alkaline flats and slopes (Howell 1944: Halse 1981). · In Wyoming~ this species is often found on sandy-clay soils or shale barrens on rims or slopes in communities dominated by Artemisia. tridentata, Atriplex qardneri, or Chrysothamnus nauseosus. At some sites it has been found on bare soils disturbed by burrowing ground squirrels. · . . ' Flowering/Fruiting Period: May-July. Population Size and Condition: The Tri-Territory Road population was estimated to contain-50-100 individuals in 1995. Due to its small stature and abundance of potential habitat, this species is probabiy far more common and widespread within the Jack Morrow Hills area .than currently kno'(,ffi. Population size is likely to fluctuate., however, depending on the availability of adequate spring moisture. Existing and Potential Threats: · Not known. Additional Comments: Prior to 1995, this species was known from five records in Wyoming, the most recent dating from 1978. Surveys by RM and WYNDD staf·f in 1995 resulted in the discovery of nearly 20 new populations in southwestern. Wyoming. · Based on it.s newly documented abundance, P. scopulina has been dropped from WYNDD's State Rare list (Fertig 1996 a).

85 DISCUSSION AND MANAGEMENT RECOMMENDATIONS PLANT COMMUNITIES Management recommendations for plant communities are given in the "Results" section of this report, under "Objective 4 11 • Those recommendations are summarized here. Given the importance of the scattered stands of mountain shrub vegetation to the desert elk herd, 'mule deer, and other species in the Jack Morrow Hills Ecosystem, these stands should be protected whenever possible from roads, pipelines, drilling locations, and other disturbances. This protection should be relatively easy, because many of the stands occupy steep slopes unsuitable for drilling sites and roads. The maps in Appendix 3 of this report will help land managers avoid disturbances to the mountain shrub vegetation, but on-the-ground surveys should be conducted before any activities proceed in the vicinity of mountain shrub stands. On-the-ground surveys will be especially important because significant stands of mountain shrub vegetation may have been missed in this project. The basin big sagebrush/lemon scurfpea vegetation on the aeolian sand in the Steamboat Rim area apparently is a unique vegetation type that deserves protection from unnecessary disturbances. The Greater Sand Dunes ACEC apparently protects much of this occurrence south and west of steamboat Rim, but part of the occurrence may lie outside the ACEC and so be vulnerable to disturbance. If so, the boundary of the ACEC should be adjusted to include the unprotected part of the occurrence (if practicable). Designation of the proposed Steamboat Mountain ACEC would protect the parts of this basin big sagebrush occurrence in the valleys northeast of steamboat Rim. PLANT SPECIES OF SPECIAL CONCERN Of the 16 plant species of special concern found in the Jack Morrow Hills Ecosystem, three are currently listed as Special Status plant species by the Rock Springs BLM (Amidon 1994). Of these, only Lesguerella macrocarpa and Antennaria arcuata are in need of special management consideration. Oryzopsis contracta has been documented to be sufficiently abundant and unthreatened statewide to no longer warrant special management attention (Fertig 1994). Populations of Lesguerella macrocarpa in the Bush Rim and Continental Peak areas have been recommended for protection from surface disturbing activities in the preferred alternative of the draft Green River Resource Area Management Plan (USDI Bureau of Land Management 1992). ACEC designation should be sought to protect the extensive Bush Rim occurrence.

86 Habitat for Antennaria·arcuata in the Oregon Gulch watershed should be managed to minimize impacts from vehicle trampling and mineral. developm~nt. Grazing has been found to be compatible with this species at other sites in the Sweetwater River Valley where stocking rates are appropriate for .the habitat (Fertig 1996 b). Several state and regionally rare plant species are potentially threatened within the ecosystem. Such species include annuals or biennials like Cryptantha scoparia, Eriastrum wilcoxii, Erioqonum divaricatum, Monolepis pusilla, Oxytheca dendroidea, Phacelia demissa, and Phacelia salina· that have fluctuating population sizes in response to favorably moist years. Such species are dependent on the establishment and maintenance of adequate seedbanks for long-term survival. The response of these species to large scale surface disturbances is poorly known. The habitats of these plants may be threatened by trampling by vehicles, mineral development activities, or livestock. Equally threatened are desert riparian species like Carex parryana that occur in habitats that are highly sensitive to disturbances. · Several rare species of the Jack Morrow Hills have small global ranges but are often locally abundant within areas of suitable habitat. Such species require little or no formal protection as long as areas of representative. habitat are maintained in good condition. These species include Astragalus nelsonianus., Ipomopsis crebrifolia, PEmstemon paysoniorum, and Phacelia scopulina. ·

87 LITERATURE CITED

Barneby, R. c. 1964. Atlas of North American Astragalus. Memoirs New York Botanical Garden 13: 1-1188.

Barneby, R. c. 1989. Intermountain Flora, Vascular Plants of the Intermountain West, USA. Volume 3, part B. Fabales. New York Botanical Garden, Bronx, NY. 279 pp.

Bayer, R. J. 1992. Allozyme variation, genecology, and phytogeography of Antennaria arcuata (Asteraceae), a rare species from the Great Basin and Red Desert with small disjunct populations. American Journal of Botany 79 (8): 872-881.

Bourgeron, P. s. and L. D. Engelking~ 1994. A preliminary vegetation classification of the western United States. The Nature Conservancy, Western Heritage Task Force, Boulder co. ·cramer, T. and R. L. Hartman. 1995. General floristic/Sensitive plant species survey of the Upper Green River Basin, Wyoming. Unpublished report prepared for the BLM Rock Springs District and Wyoming State Office by the Rocky Mountain Herbarium, Laramie, WY. 8 pp. + appendices.

Cronquist, A. 1947. Revision of the North American species of ·~ Erigeron, north of Mexico. Brittonia 6 (2): 121-300.

Cronquist, A. 1950. Notes on the Compositae of the northwestern United States. Leaflets of Western Botany. 6: 41-50.

Cronquist, A. 1994. Intermountain Flora, Vascular Plants of the Intermountain West, USA. Volume 5, Asterales. New York Botanical Garden, Bronx, NY. 496 pp.

Cronquist, A., A. H. Holmgren, N. H. Holmgren, J. L. Reveal, and P. K. Holmgren. 1977. Intermountain Flora, Vascular Plants of the Intermountain West, USA. Volume 6. The Monocotyledons. Columbia Univ. Press, NY. 584 pp.

Cronquist, A., A. H. Holmgren, N. H. Holmgren, J. L. Reveal, and · P. K. Holmgren. 1984. Intermountain Flora, Vascular Plants of the Intermountain West, USA. Volume 4. Subclass Asteridae (except Asteraceae). New York Botanical Garden, Bronx, NY. 573 pp. Dorn, R. D. 1980. Illustrated Guide to Special Interest Plants· of Wyoming. US Fish and Wildlife Service and Bureau of Land Management. 67 pp. Dorn, R. D. 1992. Vascular Plants of Wyoming, second edition. Mountain West Publ., Cheyenne, WY. 340 pp.

88 Ertter, B. 1980. A revision of the genus oxytheca Nutt. (Polygonaceae) • Brittonia 3-2 ( 1) : 70-102. Fertig, w. 1993. Survey of plant species of special concern in the Yellow Point Ridge ar~a, Sublette County, Wyoming. Unpublished report prepared for McMurry Oil Co. and the Bureau of Land Management Rock Springs District by the Wyoming Natural Diversity Database, Laramie, WY. 30 pp.

Fertig, W. 1994.1 Status report on Orvzopsis contracta, a USFWS Category 2 candidate species. Unpublished report prepared for the Bureau of Land Management Wyoming State Office by the Wyoming Natural Diversity Database, Laramie, WY. 186 pp. r , i Fertig, W. 1995 a. Status report on Thelesperma caespitosum in southwestern Wyoming. Unpublished report prepared for the Bureau of Land Management Rock Springs District by the Wyoming Natural Diversity Database, Laramie, WY. 48 pp. Fertig, w. 1995 b. Status report on Lesauerella macrocarpa in southwestern Wyoming. Unpublished report prepared for the Bureau of Land Management Wyoming State'Office and Rock Springs District by the Wyoming Natural Diversity Database, Laramie, WY. 79 pp. Fertig, w. 1995 c. status report on Cirsium aridum in west central Wyoming. Unpublished report prepared for the Bureau of Land Management Wyoming State Office, Rawlins District, and Rock Springs District by the Wyoming Natural Diver'sity Database, Laramie, WY. 105 pp. Fertig, w. 1995 d. Update and corrections to the status report on Cirsium aridum in west-central Wyoming. Unpublished report prepared for the Bureau of Land Management Wyoming state Office, Rawlins District, and Rock Springs District by the Wyoming Natural Diversity Database, Laramie, WY. 19 pp.

Fertig, w. 199.6 a. Wyoming Plant Species of Special Concern, 1996 edition. Wyoming-Natural Diversity Database, Laramie, WY. 32 pp. _ Fertig, w. 1996 b. Status report on Antennaria arcuata in central Wyoming. Unpublished report prepared for the Bureau of Land Management Wyoming State Office, Rawlins District, and Rock Springs District by the Wyoming Natural Diversity Database, Laramie, WY.

89 Fertig, w. 1996 c. Status report on Phlox opalensis in southwestern Wyoming and northeastern Utah.· Unpublished report prepared for the Bureau of Lapd Management Wyoming State Office and Rock Springs District by the Wyoming· Natural Diversity Database, Laramie, WY. 175 pp.

Fertig, W., C. Refsdal, and J. Whipple. 1994. Wyoming Rare Plant Field'Guide. Wyoming Rare Plant Technical Committee, Cheyenne, WY. Halse, R. R. 1981. Taxonomy of Phacelia sect. Miltitzia (Hydrophyllaceae). Madrono 28 (3): 121-132.

Harrison, H. K. 1972. Contributions to the study of the genus Eriastrum. II. Notes concerning the type specimens and descriptions of the species. Brigham Young Univ. Science Bulletin. 16(4): 1-28.

Hermann, F. J. 1970. Manual of the Carices of the Rocky Mountains and Colorado Basin. USDA Forest S.ervice Ag. Handbook 374: 1-397. · Hitchcock, c. L. and A. Cronquist. 1964. Pt. 2. Salicaceae to Saxifragaceae. In: ·c. L. Hitchcock, A. Cronquist, M. Ownbey, and J. W. Thompson. Vascular Plants of the Pacific Northwest. Univ. Washington Publ. Biol. 17 (2): 1-597. Hitchcock, c. L., A. Cronquist, and M. Ownbey. 1959. Pt. 4. Ericaceae.through Campanulaceae. In: c. L. Hitchcock, A. Cronquist, M. Ownbey, and J. w. Thompson~ Vascular Plants of the Pacific Northwest. Univ. Washington Publ. Bioi. 17 (4): 1-510.

Howell, J. T. :1943. Studies in Phacelia- a rev1s1on of species related to P. pulchella and P. rotundifolia. American Midland Naturalist 29 (1): 1-43. Howell, J. T. 1944. A revision of Phacelia section Miltitzia. Proceedings of the California Academy of Sciences •. 25 (15): 357-376. Jones, G. P. 1989. Survey of plant species and communities of interest in the Beaver Rim Area of Critical Environmental Concern. Unpublished report prepared for the BLM Rawlins District by the Wyoming Natural Diversity Database, Laramie, WY. 64 pp. + append~ces. Jones, G. P. 1992. Wyoming plant community classification. Wyoming Natural Diversity Database (The Nature Conservancy), Laramie WY. Unpublished. 184 pp.

90 Keck, D. D. 1947. A new Penste:inon fcrom .wyoming. Leaflets of f/ Western Botany 5: 57-58. Lesica, P. and P. F. Stickney. 1994. Noteworthy collections: Montana. Madrono 41 (3): 229-231. ·

Marriott, H. J. 1986. Status r.eport on Antennaria arcuata. Unpublished,report prepared for the us Fish and Wildlife Service by the Wyoming Natural Diversity Database, Laramie, WY. 42·PP· +appendices. Murray, D. F. ·1969. Taxonomy of Carex sect. Atratae (Cyperaceae) in the southern Rocky ~ountains. ·Brittonia 21: 55-76.

Reveal, J. L. 1969. A revision of the genus Eriogonum (Polygonaceae). Unpublished Ph.D. dissertation. Brigham Young university. 546 pp. Rollins, R. c. and E. A. Shaw. 1973. The genus Lesquerella (Cruciferae) in North America. Ha~ard Univ. Press, Cambridge, MA.

Shechter, Y. and B. L. Johnson. :1966. A new species ,of · Oryzopsis (Gramineae) from Wyoming. Brittonia 18: 342-347 • . Standley, P. c. 1916. Chenopodiales. North American Flora 21 (1): 3-93.

USDI Bureau of Land Management. 1992. Green River Resource Area resource management plan and dra.ft environmental impact statement. Rock Spring District Office, Rock Springs WY.

USDI Fish and Wildlife Service. 1993. Plant taxa for listing as Endangered or Threatened species: Notice of Review. Federal Register 58 (188): 51144-51190. Welp, L., B.• E. Nelson,· and R. L. Hartman. 1995. Status report on the general floristic inventory of the Great Divide Basin, Green and Crooks'mountains, and Upper sweetwater River drainage •. Unpublished report prepared for the Rock Springs and Rawlins Districts Bureau of Land Management by the Rocky Mountain Herbarium, University of Wyoming. 8 pp. + appendices. · · Welsh, s. L. 1983. Utah flora: Compositae (Asteraceae). Great Basin Naturalist 43 (2): 179-357. Welsh, s. L., N. D. Atwood, s. Goodrich, and L. c. Higgins. 1993. A Utah Flora, second edition, revised. Brigham Young Univ., Provo, UT. 986 pp.