218 POLYGON ACE AE 



19. E. Porteri Small. Floral stems scapiform, 2-7 cm. high; leaves basal, 

 numerous, petioled, 1-2 cm., slightly floccosc when young, soon green and glab- 

 rous; blades suborbicular or rhomboidal; involucres solitary, glabrous, turbinate; 

 perianth yellow, 6-8 mm. long; outer lobes oblong-spatulate, the inner cuneate- 

 spatulate, slightly longer. Mountain slopes: Utah. Mont. Jl-S. 



20. E. neglectum Greene. Floral stems scapiform, 1-3 dm. high; leaves 

 petioled, 2-6 cm. long; blades spatulate or elliptic or oval, loosely tomentose 

 when young, glabrous or nearly so and green at maturity; involucres campanu- 

 late; tube 2-2.5 mm. long; perianth about 8 mm. long; lobes spatulate to oblong- 

 obovate, the inner longer than the outer; achenes about 5 mm. long. E. umhelli- 

 feruni Small. E. glaberrimum aureum Gand. Mountains: Wyo.— Colo. — Nev. 

 Suhtiwnt. — Subalp. Jl-Au. 



21. E. biumbellatum Rydb. Flowering stems scapiform, 2-3 dm. high; 

 leaves short-petioled, oblanceolate, finely tomentose on both sides when young, 

 soon glabrate and green; involucres 2 mm. long, slightly tomentose; perianth 

 3'ellow, 4-6 mm. long; lobes elliptic, obtuse, the outer slightly longer. Hillsides: 

 Utah. Subinont. Jl-Au. 



22. E. stellatum Benth. Flowering stems scapiform, 1-3 dm. high, some- 

 times with a single leaf; leaves petioled, 3-8 cm. long; blades oval or rounded- 

 oval, obtuse, tomentose when young, glabrate in age above; involucres turbin- 

 ate; tube 2-2.5 mm. long; perianth 5-6 mm. long; outer lobes oblong, the inner 

 ones cuneate-spatulate; achenes 4 mm. long, sparingly villous at the apex. E. 

 croceum Small. Mountains: Wash. — -Ida. — -Colo. — Utah — Calif. Submont. — 

 Subalp. Jl-S. 



23. E. umbellatum Torr. Flowering stems scapiform, 1-3 dm. high; 

 leaves 2-6 cm. long, petioled; blades rather thick, loosely white-floccose when 

 young, in age glabrate above; involucres turbinate, tomentose; tube 3-4 mm. 

 long; divisions of the perianth spatulate, the inner somewhat longer. (?) E. 

 marginale Gand. Momitains and dry valleys: Wyo. — Colo. — Calif. — Wash. 

 Submont. — Subalp. Je-Au. 



24. E. Rydbergii Greene. Flowering stem scapiform, 1.5-2.5 dm. long; 

 leaves 2-3 cm. long, petioled, rather persistently floccose above; involucres cam- 

 panulate, tomentose; tube 3-4 mm. long; outer lobes of the perianth elliptic, the 

 inner longer, obovate; achenes villous at the apex. R. umbellatum cladophorum 

 Gand. R. rhomboideum A. Nels. Loose soil and geyser basins : n Wyo. Mont. Au. 



25. E. subalpinum Greene. Flowering stems scapiform, 1-3 dm. high; 

 leaves 2-5 cm. long, petioled, densely white-tomentose beneath; involucres 

 tomentose, turbinate; tube 3 mm. long; perianth in age turning rose-colored; 

 lobes obovate, the inner longer; achenes about 5 mm. long. E. umbellatum 

 majus Benth. Sulphur Plant. Dry mountains: Alta. — Colo. — Nev. — B.C. 

 Submont. — Mont. Je-S. 



26. E. aridum Greene. Flowering stems scapiform, 1.5-2.5 dm. long, 

 floccose; leaves 2-6 cm. long, white-tomentose beneath; involucres tomentose, 

 campanulate, 4 mm. high; perianth purplish in age; outer lobes elliptic, the inner 

 ones spatulate, somewhat longer; achenes villous at the apex. E. latum Small. 

 Dry gravelly soil: Mont. — Colo. — Nev. — Wash. Submont. — Mont. Je-Au. 



27. E. heracleoides Nutt. Flowering stems 2-4 dm. high; leaves 5- 10 cm. 

 long, short-petioled, loosely floccose above, densely white- or yellowish-tomen- 

 tose beneath; inflorescence compound-umbellate; involucres campanulate, vil- 

 lous; tube 3 mm. long; perianth 4 mm. long; achenes hairy above. Dry slopes: 

 Mont.— Wyo.— Utah— Nev.— B.C. Submont.— Mont. 



28. E. lachnogynum Torr. Flowering stems scapiform, 1-3 dm. high; 

 leaves crowded, basal, oblanceolate or oblong-oblanceolate, petioled, acute, 

 silvery-silky above, grayish tomentose beneath, with revolute margins; bracts 

 lanceolate or subulate, rarely verticillate; involucres silky-tomentose, 3-4 mm. 

 high, campanulate; lobes oblong; perianth campanulate, tomentose, 3 mm. high, 

 yellow; fruit villous. Dry plains and canons: Kans. — -Colo. — 'Ariz. — Tex. 

 Son. — Plain. Je-Au. 



