THISTLE FAMILY 991 



linear-filiform lobes, 1-1.5 mm. wide, or the upper simple and linear-filiform, 

 somewhat fleshy; heads in a corymb if orm inflorescence, numerous; involucres 

 almost cylindric, 6-7 mm. high, about 4 mm. in diameter; bracts linear, gradually 

 acute, the calyculate ones small, subulate; ligules pale yellow, 7-8 mm. long; 

 achenes strigose-hispidulous. Mountain valleys and high plains: N.M. Colo. 

 Ariz. Submont. Subalp. Au-S. 



29. S. spartioides T. & G. Stem 3-6 dm. high, leafy throughout, often 

 several from one root; leaves glabrous, narrowly linear, entire; heads corymbose; 

 involucre nearly cylindric; bracts about 12, carinate, linear, acute, the calyculate 

 ones subulate, minute; ligules few, 8-10 mm. long; achenes silky-canescent. 

 Banks and plains: Tex. Neb. Wyo. Ariz. Plain Mont. Jl-O. 



30. S. longilobus Benth. Stem 3-10 dm. high, white-tomentose, at least 

 when young, leafy; leaves white-tomentose, pinnately divided into linear-filiform 

 divisions, or the upper entire and linear-filiform; heads corymbose, 12-15 mm. 

 high; involucres campanulate, 10^12 mm. broad, floccose at the base; bracts 

 linear, carinate, short-acuminate; ligules 10-12 mm. long; achenes finely strigose- 

 canescent. S. filifolius Nutt., not Bergius. Plains and valleys: Tex. Colo. 

 Utah Ariz.; Mex. Son. Submont. Ap-Au. 



31. S. anacletus Greene. Stems 1-3, few-leaved, terete and slightly striate; 

 basal leaves obovate or broadly spatulate, obtuse or mucronate, copiously callous- 

 denticulate, rather thick, 5-15 cm. long, with a distinct winged petiole; stem- 

 leaves few and small, from spatulate to narrowly lanceolate, sessile and often 

 subentire; cyme corymb if orm; involucres campanulate, 10-12 mm. high and 

 12-15 mm. broad; bracts linear-lanceolate, acuminate, about two-thirds as long 

 as the disk; ligules bright yellow, about 8 mm. long; achenes glabrous. S. 

 toluccanus microdonthes A. Gray. (?) S. Wootonii Greene. Damp places in 

 the mountains: Ariz. N.M. Colo. Submont. Subalp. My-Jl. 



32. S. glaucescens Rydb. Stem 2-7 dm. high, striate, shining, glabrous 

 or slightly hairy at first; lower leaves 5-10 cm. long, with winged petioles; blades 

 spatulate or oblanceolate, or even oval, callous-dentate or subentire, somewhat 

 glaucous; upper stem-leaves reduced, lanceolate, sessile; cyme corymbose, dense; 

 heads campanulate, about 1 cm. high; bracts linear-lanceolate, acute, black- 

 tipped, about two-thirds as long as the disk; ligules dark yellow, about 8 mm. 

 long; achenes glabrous. Wet places: Mont. n Wyo. Ida. Plain Submont. 

 Au. 



33. S. lugens Richards. Stem slender, terete, about 3 dm. high; basal 

 leaves 5-10 cm. long, narrowly oblanceolate, sinuate-dentate; upper stem-leaves 

 much reduced, linear or linear-lanceolate; cyme corymbiform; heads 5-7, cam- 

 panulate, about 1 cm. high, 8-12 mm. broad; bracts rather thick, linear-oblong or 

 lanceolate, acute, conspicuously black-tipped; rays about 8 mm. long; achenes 

 glabrous. Wet places: Subarctic America Man. Ida. Alaska. Subalp. Je-JL 



34. S. atratus Greene. Plant tomentose when young, tardily becoming: 

 more glabrate in age; stem 3-6 dm. high, terete; basal leaves distinctly petioled,. 

 1-2 dm. long; blade spatulate or oblanceolate, callous-denticulate, tapering at the 

 base; upper stem-leaves lanceolate and sessile; cyme compound, corymbiform; 

 heads very numerous, small; involucre 6-10 mm. high, almost cylindric; bracts 

 broadly linear, acute; ligules light yellow, 6-8 mm. long; achenes glabrous. S. 

 lugens foliosus A. Gray, in part. Mountain sides: Colo. Utah N.M. Sub- 

 mont. Subalp. Je-Au. 



35. S. milliflorus Greene. Stem persistently tomentose, about 1 m. high; 

 basal leaves petioled, 2-3 dm. long, tomentose on both sides; blades oblanceolate, 

 callous-dentate; stem-leaves lanceolate, sessile, acuminate; heads very numerous, 

 in a compound flat-topped cyme; involucres narrow, cylindric, 6-7 mm. high, 

 about 12-flowered; bracts about 8, narrowly linear; ligules 3 or 4, 3-4 mm. long; 

 achenes glabrous. Mountains: Colo. Mont. Jl. 



36. S. foliosus (A. Gray) Rydb. Stem floccose-tomentose when young, 

 2-3 dm. high, terete; lower leaves oblanceolate, 7-10 cm. long, sinuate-denticu- 

 late, acute, tapering at the base and short-petioled; upper leaves lanceolate or 



