972 CARDUACEAE 



lucres 5-8 mm. broad, hemispheric, densely tomentose; bracts oval, scarious- 

 margined; flowers 30-40, yellowish brown. Mountains: i\Iont. — Ore. Submonl. 

 Jl-Au. 



53. A. Flodmanii Rydb. Perennial, with a branched rootstock; stem 

 slender, 3-5 dm. high, tomentose, grooved, simple up to the inflorescence; leaves 

 many, 3-7 cm. long, white-tomentose on both sides, usualty twice pinnatifid into 

 lanceolate or linear divisions, the upper less divided or simple; heads numerous, 

 in a rather dense leafy panicle; involucre about 3 mm. high, 2.5-3.5 mm. broad; 

 bracts floccose, the outer lance-ovate, acute, the inner bracts elhptic, obtuse; 

 flowers 20-30. Hillsides: Mont.— Wyo.— Ore.— (? Utah). Submont. 



54. A. discolor Dougl. Perennial, with a horizontal rootstock; stem 5-7 

 dm. high, striate, slightly floccose when young, glabrate in age; leaves 4-7 cm. 

 long, sessile, loosely floccose when young, but soon glabrous above, white-tomen- 

 tose beneath, thin, pinnatifid, with hnear or linear-lanceolate acute divisions; 

 divisions of the larger leaves again cleft or toothed; involucre 3.5-4 mm. high 

 and as broad; bracts arachnoid-tomentose, yeUowish, lanceolate to elhptic, 

 acutish; flowers 35-50. Rocky situations : Mont. — Ida. — Wash. — B.C. Sitbtnont. 



55. A. Michauxiana Besser. Perennial, more or less suffruticose at the 

 base, with a much branched caudex; stem 2-4 dm. high; leaves 3-6 cm. long, 

 subsessile, pinnately or bipinnately divided or cleft into linear or lanceolate or 

 rarely broader, often toothed divisions, white-tomentose beneath; involucre 3-4 

 mm. high, 5-7 mm. broad; outer bracts hnear-lanceolate, acute, the inner oval, 

 obtuse; flowers 25-40. A. discolor A. Gray, mainly. Hills and mountain sides: 

 Sask.— B.C.— Wash.— Utah— Colo. Plain— Mont. 



56. A. graveolens Rydb. Perennial, with a cespitose slender caudex; 

 stems numerous, branched, glabrous; leaves twice or thrice pinnatifid into linear 

 or lance-hnear divisions; margins more or less re volute; heads numerous, in a 

 narrow panicle, with racemiform branches, nodding; involucres about 4 mm. 

 broad, glabrous; bracts ovate, with brownish scarious margins; corollas brown, 

 glabrous, 15-30. A. subglabra A. Nels. Banks and hillsides: Alta. — Wyo. — 

 Ore. — B.C. Submont. Jl-Au. 



57. A. tenuis Rydb. Perennial, with a creeping cespitose rootstock; stem 

 slender, glabrous or minutely puberulent, 3-4 dm. high; leaves 2-3 cm. long, 

 deeply pinnatifid into 5-7 linear, acute, divergent segments; inflorescence with 

 raceme-like slender branches; involucres about 4 mm. high, 2-3 mm. wide; bracts 

 glabrous or minutely puberulent, with scarious margins; corollas 10-20, brown- 

 ish. Sandy gulches: Mont. — n Wyo. Submont. Jl-Au. 



58. A. Wrightii A. Gray. Perennial, suffruticose at the base; stem 3-5 dm. 

 high; leaves pinnatifid, with linear-filiform divisions, slightly pubescent when 

 young, soon glabrate above, white-tomentulose beneath, with revohite margins; 

 heads in narrow, dense panicle; involucres about 3 mm. high, 1.5-2 mm. broad, 

 shghtly tomentose; bracts oval; flowers 10-15, yellowish. Dry hiUs and moun- 

 tains: N.M. — s Colo. — Utah — Ariz. Son. — Submont. Au-S. 



59. A. Bakeri Greene. Perennial, with a cespitose caudex; stem decum- 

 bent at the base, loosely branching, 3-7 dm. high; leaves green and glabrous 

 above, white-tomentose beneath, with revolute margins, the lower pinnatifid, 

 with narrowly linear segments, the upper entire and narrowly linear; heads in 

 an open loose panicle; involucres 2.5-3 mm. high, about 2 mm. broad, only slightly 

 tomentose; outer bracts linear, the inner oval, with broad scarious margins. 

 Canons and valleys: N.M. — Colo. — Ariz. Submont. Au-S. 



60. A, Carruthii Wood. Perennial, with a short cespitose caudex; stem 

 3-5 dm. high, white-tomentose, very leafy; leaves pinnatifid, with narrowly 

 linear divisions, with revolute margins, densely white-tomentose on both sides, 

 the uppermost often entire, linear-filiform; heads very numerous in a dense 

 panicle; involucres about 2.5 mm. high, 2 mm. broad, densely tomentose; outer 

 bracts lanceolate, the inner oval, broadly scarious-margined. A . kansana Britton. 

 A . coloradensis Osterhout, a form with broader segments. Dry plains and prairies: 

 Mo.— Colo.— Utah— Tex. Son.— Mont. Au-S. 



