886 CARDUACEAE 



34. A. brevibracteatus Rydb. Stem 5-6 dm. high, glabrous, tinged with 

 purple; basal leaves about 1 dm. long, with short winged petioles; blades spatu- 

 late or oblanceolate, crenate-serrate, glabrous; upper stem-leaves lanceolate, 

 half clasping; involucre 5-7 mm. high, nearly 1 cm. broad; bracts linear-lanceo- 

 late, firm, with a narrowly rhomboid green tip; ligules blue, 8 mm. long. Low 

 ground: Wash. Mont. Submont. Au-S. 



36. A. laevis L. Stem 3-12 dm. high, rigid, glabrous, glaucous; basal leaves 

 with winged petioles; blades ovate or lanceolate, more or less serrate, glabrous 

 and glaucous; upper stem-leaves ovate, subcordate or auriculate-clasping; invo- 

 lucres 8-9 mm. high, about 1 cm. broad; ligules blue. Open woodlands: Ont. 

 La. N.M. B.C. Plain Mont. Au-O. 



36. A. Geyeri (A. Gray) Howell. Stem 5-10 dm. high, glabrous; lower 

 leaves 1-2 dm. long, with winged petioles; blades oblanceolate, entire or sparingly 

 serrate, glabrous, glaucous; involucres about 8 mm. high and 1 cm. wide; ligules 

 blue, 8-10 mm. long; achenes glabrous. Valleys: Alta. S.D. Colo. Wash. 

 Submont. Mont. Jl-S. 



37. A. subsalignus Rydb. Stem 6-10 dm. high; leaves nearly erect, gla- 

 brous, glaucous, entire, clasping, 5-10 cm. long, 6-7 mm. wide; involucres about 

 7 mm. high and 8 mm. wide; ligules bluish or bluish purple, about 8 mm. long; 

 disk-flowers dark, red-purple. Valleys: Colo. Submont. Au. 



38. A. Scribneri Rydb. Stem 3-6 dm. high, glabrous; basal leaves 1-2 dm. 

 long, with wing-margined petioles; blades thin, ovate, acute, sharply serrate- 

 dentate, glaucous, glabrous; stem-leaves ovate or ovate-lanceolate, sessile and 

 clasping; panicle small, with 5-10 heads; bracts glabrous; ligules about 8 mm. 

 long. Valleys: Mont. Submont. Au. 



39. A. Porteri A. Gray. Stems 2-4 dm. high, glabrous, simple or branched 

 above; leaves linear, or the lower oblanceolate, 5-10 cm. long, divergent, glabrous, 

 or the lower hirsute-ciliate; heads numerous; involucres 4-5 mm. high, 6-7 mm. 

 broad; ligules white, 5-6 mm. long. Mountains: Colo. Submont. Mont. Jl-O. 



40. A. subracemosus Rydb. Stem 5-6 dm. high, simple, strict, sparingly 

 strigose; leaves oblanceolate or the upper linear, sessile, 4-8 cm. long, more or 

 less scabrous, scabrous-ciliate on the margins, entire; involucres about 8 mm. 

 high and 1 cm. broad; bracts in 3-4 series, with oblanceolate green tips. Rocky 

 hillsides: Mont. Submont. S. 



41. A. salicifolius Lam. Stem 5-20 dm. high, paniculately branched; 

 leaves lanceolate, firm, glabrous or scabrous, 6-10 cm. long, the lower more or 

 less dentate; involucres 6-8 mm. high, 8-10 mm. broad; bracts with narrowly 

 oblanceolate green tips or the outer nearly wholly green; ligules purple or violet, 

 rarely white, 6-8 mm. long. Wooded banks: Me. Fla. Tex. Colo. B.C. 

 Plain Submont. Au-O. 



42. A. paniculatus Lam. Stem 5-20 dm. high, paniculately branched; 

 leaves oblong-lanceolate to narrowly linear-lanceolate, mostly attenuate, thin, 

 glabrous, sharply denticulate or the upper entire; involucres 5-6 mm. high, 8-10 

 mm. wide; bracts with narrowly linear-lanceolate green tips; ligules white or 

 rarely pink or pale lilac, 7-8 mm. long. Wooded banks: N.B. Va. Colo. 

 Sask. Plain Submont. Au-O. 



43. A. hesperius A. Gray. Stem 4-10 dm. high, paniculately branched; 

 leaves lance-linear, entire or rarely denticulate, 5-15 cm. long, thin, glabrous or 

 nearly so, hispid-ciliolate on the margins; involucres 7-8 mm. high, nearly 1 cm. 

 broad; outer bracts green, the inner ones with narrowly lanceolate green tips, of 

 the same length or the outer slightly shorter; ligules violet or white, 7-8 mm. 

 long. Along streams: N.M. Colo. Calif.' n Mex. Son. Au-O. 



44. A. fluviatilis Osterh. Stem slender, 6-10 dm. high, leafy and branched; 

 leaves lance-linear, sessile, somewhat clasping, the larger 1 dm. long, entire or 

 nearly so; inflorescence paniculate; involucres 6-7 mm. high, nearly 1 cm. broad; 

 bracts in 4 series, oblanceolate, acute, with oblanceolate green tips; ligules lilac 

 to purple. A. coerulescens Rydb. (Fl. Colo.), not DC. Along streams: Wyo. 

 Utah Colo. la. Plain Submont. S. 



