858 CARDUACEAE 



30. C. elegans Greene. Low shrub, 1-3 dm. high, branched; branches gla- 

 brous, straw-colored; leaves narrowly Unear, 1-3 cm. long, 1-2 mm. wide, 3- 

 nerved, strongly twisted; involucres about 6 mm. high; bracts lanceolate, acute, 

 glabrous; achenes sparingly strigose. Plains and dry valleys: Colo. — N.M. 

 Siibmont, Jl-Au. 



31. C. linifolius Greene. Shrub, 6-10 dm. high, fastigiately branched; 

 branches glabrous, white, striate; leaves ascending, hnear-lanceolate, acute, 3- 

 nerved, 2-A cm. long, 5-8 mm. wide; involucres about 7 mm. high; bracts oblong, 

 obtuse; achenes densely hirsute-strigose. B. linifoUa A. Ncls. Dry plains and 

 river bottoms: Wyo. — Colo. Plain — SubmonL Au-S. 



32. C. stenolepis Rydb. Low shrub, 2-3 dm. high, somewhat splnescent; 

 branches short, erect, glabrous or finely puberulent above; leaves narrowly 

 lance-linear, 1-2 cm. long, 2-4 mm. wide, somewhat twisted; involucres about 

 8 mm. long; achenes hirsute-strigose. Dry hills: Mont. — Wyo.^ — Utah — Ida. 

 Plain — Suhmont. Au-S. 



33. C. glaucus A. Nels. Shrub, 3-10 dm. high; leaves ascending, narrowly 

 linear-lanceolate, acute, obscurely 3-nerved, 2-4 cm. long, usually somewhat 

 twisted, bluish green; bracts subcarinate, membranous, glabrous; achenes silky- 

 strigose. C. serrulatus (Torr.) Rydb. B. Doiiglasii serrulata A. Gray. C. leuco- 

 cladus Greene. Dry plains and slopes: Wyo. — Colo. — Utah — Ariz. SubmonL 



34. C. viscidiflorus (Hook.) Nutt, Shrub, 6^12 dm. high; leaves linear, 3-5 

 cm. long, 3-nerved, 2-4 mm. wide; involucres about 7 mm. high; bracts thin, 

 oblong; achenes strigose. B. Douglasii A. Gray. Dry plains: Mont. — Wyo. — 

 Calif. — Wash. Plain — Son. Jl-S. 



35. C. latifolius (D. C. Eat.) Rydb. Low shrub; leaves oblanceolate or 

 oblong, acute. 3-5-nerved, glabrous, 2-4 cm. long, 5-8 mm. broad; involucres 6 

 mm. high. LinosyHs viscidiflora latijolia D. C. Eat Mountains: Nev.— Ida.— 

 Utah. Suhmont. S. 



36. C. lanceolatus Nutt. Undershrub, 1-3 dm. high; branches straw- 

 colored or gray, finely puberulent; leaves linear-lanceolate, 2-4 cm, long; involu- 

 cres 7-8 mm. long; outer bracts lanceolate, acute, the inner oblong, obtuse, gla- 

 brous, or the outer puberulent; achenes hispid-strigose. B. Douglasii lanceolafa 

 A. Gray. B. Douglasii spathulata M. E. Jones, a form with short lower leaves. 

 Dry plains and hills: Mont, — Colo. — Nev. — Wash. Plain — SubmonL Au-S. 



37. C, puberulus (D. C. Eat.) Greene. Undershrub, 1-3 dm. high; branches 

 finely puberulent; leaves narrowly linear, 2-4 cm. long, densely puberulent; 

 involucres 6-7 mm. long; bracts glabrotis, lanceolate or the inner linear, acute, 

 somewhat viscid; achenes sparingly strigose. B. Douglasii puherula A. Gray. 

 Dry plains and hills: B.C. — Mont. — Colo, — Calif. Son.— Mont, Jl-S. 



38. C. marianus Rydb. Undershrub, 1-2 dm. high, with a woody thick 

 caudex; leaves linear or the lower linear-oblanceolate, acute, thick, 1-2 cm. long, 

 1-15 mm. wide; bracts yellowish, glutinous, erose-ciliate on the margins, the 

 outer ovate, acutish, the inner spatulate-oblong, rounded at the apex; achenes 

 sparingly strigose. Valleys: Utah. Son. Jl. 



39. C. leiospermus (A. 'Gray) Greene. Shrub, 3-6 dm. high; branches 

 white-tomentose, or in age glabrate; leaves sparse, involute-filiform (in var. 

 breviata about 1 cm. long or less); bracts oblong, or the inner linear-oblong^ 

 rounded at the apex; achenes glabrous. B, leiosperma A. Gray. Desert regions: 

 s Utah — Nev. L. Son, 



40. C. glareosus (M. E. Jones) Rydb. Undershrub, growing in dense 

 clmnps, about 3 dm. high; leaves linear-oblanceolate, the upper reduced, oblong, 

 and bract-like; inflorescence cor\Tnbiform; bracts about 4 in each vertical row, 

 sparsely lacerate on the margins and white-tomentulose, obtuse or rounded at the 

 apex, the lower small, ovate, the upper with conspicuous thickened tips, linear; 

 corolla fully 1 cm. long. B. glareosa M. E. Jones. Mesas: c Utah. SubmonL O. 



♦ 41, C. Vaseyi (A. Gray) Greene. Perennial, with a cespitose woody caudex, 

 1-2 dm. high, glabrous; leaves linear-oblanceolate, obtuse, thick, glabrous, 1-2.5 



