THISTLE FAMILY 887 



45. A. Osterhoutii Rydb. Stem branched and leafy, 5-10 dm. high; leaves 

 5-12 cm. lonfz;, S mm. wide or less, those of the branches much smaller; involucres 

 7-8 mm.; bracts linear to oblanceolate, apiculate; ligules white or rarely pinkish, 

 nearly 1 cm. long. Along ditches and streams: Colo. — Sask. — Alta. Plain. 

 Au-S. 



46. A. laetivirens Greene. Stem erect, 3-6 dm. high, red or purplish; 

 leaves lanceolate or oblong-lanceolate, thin, light green, somewhat glaucescent; 

 involucres 8 mm. high and about 1 cm. wide; ligules 8-10 mm. long, white or 

 pinkish. Along streams: Colo. — Wj^o. — Ida. Suhmont. Au-S. 



47. A. longulus Sheld. Stem strict, branched above, 6-15 dm. high, his- 

 pid in lines; leaves narrowly linear, 3-10 cm. long, sessile, glabrous on both sides 

 or scabrous above; inflorescence paniculate; involucres 4-5 mm. high, 6-7 mm. 

 broad; bracts acute, the outer often wholly green; ligules 6 mm. long, white or 

 lilac. Swampy ground: Sask. — Minn. — Neb. — Colo.— B.C. Plain. Jl-S. 



48. A. roseolus Rydb. Stem 3-5 dm. high, often purple-tinged; leaves 

 linear, glabrous or nearly so, 5-10 cm. long, 5-12 mm. wide; involucres about 5 

 mm. high, 8-9 mm. broad; bracts often wholly green, with broadly lanceolate 

 tips; rays rose-colored, 5-6 mm. long. Meadows: Mont. Suhmont. Au. 



49. A. Franklinianus Rydb. A perennial, with a horizontal rootstock; 

 stems 4-10 dm. high, simple; leaves narrowly linear, entire, scarcely clasping, 

 rather firm, dark green, glabrous, 7-15 cm. long, less than 1 cm. wide; involucres 

 8 mm. high, fully 1 cm. broad; bracts linear, attenuate; ligules purple, 8-10 mm. 

 long. A. salicifolius Richards., not Lam. Wet meadows: Sask. — Mont. — Ida. 

 — Mack. Boreal — Mont. 



50. A. corymbiformis Rydb. Stem strict, about 3 dm. high, branched 

 above; leaves linear, 5-8 mm. long, half-clasping; inflorescence leafy, corymbi- 

 form; involucres 6 mm. high, 8 mm. broad; bracts linear-lanceolate, with an ob- 

 lanceolate green tip; ligules white or purplish, about 7 mm. long. Meadows: 

 Colo. Submont. Au. 



51. A. junciformis Rydb. Stem slender, 3-5 dm. high, simple below; 

 leaves narrowly linear, 4-8 cm. long, 2-4 mm. wide; involucres about 6 mm. high, 

 about 1 cm. broad; the inner bracts linear, acute, with green lanceolate tips, the 

 outer oblong or oblanceolate, obtuse, often almost wholly green; ligules white, 

 6-8 mm. long. ]\Ieadows and swamps: Sask. — Wis. — Colo. — Wash. — B.C. Plain. 



52. A. lonchophyllus Greene. Stem erect, 4-6 elm. high, reddish-purple; 

 leaves 5-10 cm. long, narrowly lanceolate, acute, entire, sessile, firm, green and 

 glabrous, 1-nerv^ed; inflorescence paniculate; involucres about 7 mm. high and 

 1 cm. broad; bracts linear, acute, more or less tinged with purple; ligules rose- 

 purple. Mountains: Colo. Mont. Au. 



53. A. eriocaulis Rydb. Stem about 8 dm. high, leafy, purplish; stem- 

 leaves 3-7 cm. long, more or less auriculate-clasping; inflorescence a round-topped 

 panicle; involucres 8 mm. high, 10-12 mm. broad; bracts linear, acute, more or 

 less ciliate, the outermost almost wholly green; ligules purple, 8-10 mm. long. 

 Motmtain meadows: Ida. Submont. Au. 



54. A. leucopsis Greene. Stem 3-6 dm. high, straw-colored, racemosely 

 paniculate above, hispidulous in the inflorescence, linear, 5-10 cm. long, 5-10 mm. 

 wide, thick, pale green, strongly scabrous-ciliolate on the margins; heads mostly 

 solitary at the ends of the many short branches; involucres turbinate, about 8 

 mm. high and broad; bracts well imbricate, oblanceolate, with a narrowly rhom- 

 bic green lip; ligules 8 mm. long, white or pale violet. Along ditches: Utah. 

 Son. S. 



55. A. subcaudatus Rydb. A perennial, with a creeping rootstock; stem 

 3-6 dm. high, more or less purple; lower leaves 1-2 dm. long, 4-10 cm. wide, 

 often sparingly dentate with ascending sharp teeth, dark green; upper leaves 

 sessile; panicle open, with rather few heads; involucres 7-8 mm. high, about 12 

 mm. broad; bracts only slightly white-margined below; rays purple, about 1 cm. 

 long. Mountain meadows: Alta. — Wyo. — Ida. — B.C. Submont. — Mont. Je- 

 Au. 



