THISTLE FAMILY 981 



26. A. subplumosa Greene. Stem 3-S dm. high, more or less villous and 

 somewhat glandular above; lower leaves oblanceolate, wing-pet ioled, 5-10 cm. 

 long, denticulate or entire; upper stem-leaves sessile, lanceolate or oblanceolate ; 

 heads 1-5; involucres hemispheric, 10-15 mm. high; bracts linear-lanreolate, 

 acute; achenes hirsute, rarely almost glabrous. A. Chamissonis longinodosa A. 

 Nels. A. subplumosa silvatica A. Nels., in part, a low form. Mountain meadows; 

 Mont. — Colo. — Utah. Mont. — Siibalp. Je-Au. 



27. A, tomentulosa R^^db. Stem villous, about 4 dm. high; leaves ob- 

 lanceolate, obtuse, sessile or the lower with short-winged petioles, denticulate, 

 finely villous-pubescent, almost tomentulose, with two pairs of stronger veins, 

 the larger 13 cm. long, somewhat yellowish; heads few, hemispherical; involucres 

 about 12 mm, high and 2 cm. broad; bracts ovate or ovate-oblong, villous; rays 

 light yellow, over 1 cm. long; achenes sparingly hispidulous. (?) A. sir Ida A. 

 Nels. Mountains : Wyo. — Colo. Mont, Au. 



28. A. Chamissonis Lessing. Stem 4-6 dm. high, softly villous, very 

 leafy; lower leaf-blades oblanceolate, tapering into winged petioles, which are 

 connate-clasping, usually with 5 stronger veins, 7-15 cm. long, denticulate or 

 entire; upper leaves lanceolate, sessile; heads cj-mose-paniculate; involucres 

 hemispheric, about 1 cm. high, hirsute-villous; bracts narrowly linear-lanceolate; 

 achenes hirsutulous. Wet places: Sask. — Mont. — Ida. — B.C. Submont. Jl- 

 Au. 



29. A. rhizomata A. Nels. Stem 2-5 dm. high, densely short-tomentose; 

 leaves 5-7 pairs, oblong-lanceolate, obtuse or acute, 6-9 cm. long, denticulate or 

 entire, densely tomentose, the lower tapering into winged petioles, which are 

 sheathing at the base, the upper sessile; heads 1-5; involucres 10-12 mm. high, 

 more or less villous-tomentose; bracts oblong or oblong-lanceolate, obtuse or 

 acute; achenes sparingly hirsutulous. A. lanulosa Greene. A. exigua A. Nels., a 

 depauperate form. Valleys: Mont.— Colo.—Utah — Ida. MonL—Subalp. 3\- 



Au. 



30. A, foliosa Nutt. Stem 3-6 dm. high, tomentose, slightly glandular- 

 puberulent in the inflorescence; leaves linear or Unear-lanceolate, denssly tomen- 

 tulose, entire or rarely denticiJate, 5-10 cm. long, the lower petioled, the upper 

 sessile; heads 1-7; involucres about 8 mm. high, hemispheric, tomentose, at least 

 at the base; bracts linear or lance-linear, acute; achenes hispidulous. Wet places: 

 Mack.— Colo.— Utah— Alaska. SubmonL—MmL Jl-Au. 



31. A. ocreata A. Nels. Stem 2-4 dm. high, sparingly puberulent, some- 

 what glandular so above; leaves linear-lanceolate, entire, or sparingly denticu- 

 late finely puberulent, but green, the lower tapermg into petioles, more or less 

 sheathing, the upper sessile; heads 3-5; involucres somewhat turbinate, 7-9 mm, 

 high finely puberulent; achenes glabrous or sparmgly hispidulous. Valleys: 

 Mont.— Wyo.— Utah, Plain— Submont, Jl~Au. 



32 A. celsa A. Nels. Stem 4-6 dm. high, sparmgly villous, and glandular- 

 puberulent in the inflorescence; leaves fr-8 pairs, puberulent and glandular- 

 eranuliferous, green, linear-oblanceolate or linear-oblong, the lower petioled, 

 with sheathing bases; upper leaves sessile, lanceolate; heads 3-5, cop-mbose- 



involucres hemispheric, nearly 1 cm. high, villous ss weU as glandular- 

 uuuc.u.ent; bracts linear-lanceolate, acute; achenes sparmgly hirsutiflous. Per- 

 haps not distinct from the preceding. W^et meadows: Mont.— Colo.— Ida, 

 Svhmont.^MonL Jl-Au, . ^ . , 



33 A nibricaulis Greene. Stem 3-6 dm. high, villous, often tinged with 

 reddish purple; leaves lanceolate, &-15 cm. long, the lower tapering mto wmged 

 ritioles all thin, triple-ribbed, sinuate-dentate or -denticulate, short-pubescent 

 on both sides; heads many, paniculate; involucres about 1 cm high nearly 2 cm 

 broad; bracts lanceolate, acutish, sparsely hirsute; holies about 12 i^m long; 

 achenes hirsute; pappus browish, plumose. Meadows: B.C.— Mont.— (? Alaska). 

 Sub?nmt ,—M anL Je-Au, . , .„ » , 



34 A Rydbergii Greene. Stem 2^ dm. high, sparmgly villous; basal 

 Ipaves" oblanceolate, entire, petioled; stem-leaves 3-4 pairs, glabrate or sparmgly 



cymose 



