856 CARDUACEAE 



webby; corolla narrowly tubular-funnelform, about 15 mm. long. Hills: N.M. 

 Colo. Son. Submont. Au-S. 



7. C. Howardii (Parry) Greene. Low shrub, 1-3 dm. high; branches white- 

 tomentose, ascending; leaves linear-filiform, 3-5 cm. long; involucres 10-12 mm. 

 high; bracts lanceolate-attenuate, tomentose as well as arachnoid; flowers scarcely 

 1 cm. long. B. Howardii A. Gray. Dry hills: Neb. Wyo. Colo. Plain 

 Submont. Jl-S. 



8. C. Greenei (A. Gray) Greene. Perennial, with a woody caudex and deep 

 taproot; stems 1-3 dm. high, glabrous and shining, with a white bark; leaves 

 narrowly linear, glabrous, scabrous on the margins, more or less twisted; cyme 

 flat-topped; heads numerous, 6-8 mm. high; bracts chartaceous, lanceolate. B. 

 Greenei A. Gray. C. scoparius Rydb. Plains: Colo. N.M. Utah. Submont. 

 S-O. 



9. C. filifolius Rydb. Small shrub, about 3 dm. high, very bushy; leaves 

 very narrow, linear-filiform, glabrous except the minutely scabrous-ciliolate 

 margins; cyme large, flat-topped; heads very numerous, 5-6 mm. high, turbin- 

 ate; bracts lanceolate-acuminate, the outer with green tips. Plains: Colo. 

 N.M. Submont. Mont. Jl-Au. 



10. C. albidus (M. E. Jones) Greene. Shrub, 3-8 dm. high; stem slightly 

 tomentulose and viscid; leaves filiform, 2-4 cm. long, about 1 mm. wide, very 

 numerous, slightly if at all tomentulose; heads f astigiate-corymbose ; involucre 

 8-10 mm. high; bracts coriaceous, lanceolate, the outer subulate-acuminate, the 

 inner merely acute; corollas straw-colored; achenes hirsutulous. B. albida M. E. 

 Jones. Arid regions: Utah Nev. se Calif. Son. My-Au. 



11. C. collinus Greene. Shrub, 2-4 dm. high, greenish, obscurely cinereous, 

 tomentulose only when young; leaves linear-filiform, soon glabrate and gummy; 

 heads few; bracts carinate, 3 or 4 in each series, the outer lanceolate, acuminate, 

 the inner cuspidate-attenuate. B. collina A. Nels. Hills: Colo. Wyo. Sub- 

 mont. Au. 



12. C. wyomingensis A. Nels. Tufted shrub, 2-4 dm. high, bushy; 

 branches yellowish green, slightly tomentulose when young; leaves narrowly 

 linear, viscidulous; inflorescence thyrsoid, leafy; bracts somewhat indistinctly 5- 

 ranked, lanceolate gradually short-acuminate. Saline soil and dry plains: Colo. 



-Wyo. Submont. Jl-Au. 



13. C. formosus Greene. Low shrub, branched from the base, about 3 dm. 

 high; stem white-tomentose; leaves linear, spreading, white-tomentose; bracts 

 6 or 7 in each vertical rank, glabrous, the outer ovate, the inner longer, oblong- 

 linear, obtuse or acutish. Hills: w Colo. Son. Au. 



14. C. virens Greene. Shrub, 1-2 m. high; leaves 4-6 cm. long, linear; 

 heads many in large corymb; involucres 6-7 mm. long; bracts in 4 series; teeth 

 of the corolla obtusish, one-fourth as long as the throat, not spreading. Plains: 

 se Colo. Son. S. 



15. C. graveolens (Nutt.) Greene. Shrub, 1-1.5 m. high, green, pannose 

 only w r hen young; leaves linear, 4-7 cm. long; heads numerous in a compound 

 corymb; involucres about 8 mm. long; bracts lanceolate, in 4 series; lobes of the 

 corolla lanceolate, more than half as long as the throat, spreading. B. graveolens 

 glabrata A. Gray. C. falcatus Greene. C. laetevirens Greene. Canons, bad- 

 lands, and dry hills: Neb. N.M. Utah Mont. Plain Submont. Au-O. 



16. C. patens Rydb. Shrubby, half a meter or so high; leaves 6-8 cm. 

 long, about 1 mm. broad; bracts lanceolate, acute, carinate, glabrous; corolla- 

 lobes about 1 mm. long. Dry plains and hills: Colo. Plain Submont. Je-Jl. 



17. C. pinifolius Greene. Shrub, 3-5 dm. high; branches erect, yellowish 

 green and soon glabrous, slightly resinous; leaves 4-5 cm. long, almost filiform; 

 heads in small panicles; involucres about 8 mm. high; bracts in 3 series, narrowly 

 lanceolate. Dry hills and plains: Colo. N.M. Nev. Ore. Son. Submont. 



18. C. concolor (A. Nels.) Rydb. Shrub, 3-4 dm. high, woody at the base; 

 branches yellowish green, pannose only when young; leaves linear, somewhat 



