888 CARDUACEAE 



56. A. occidentalis Nutt. Stem strict, 2-10 dm. high; lower leaves 1-2 dm. 

 long, linear-lanceolate, entire or few-toothed, dark green; upper leaves lance- 

 linear or linear, those of the corymbiform inflorescence much reduced; involucres 

 5-7 mm. high, 10-12 mm. broad; ligules 6-8 mm. long. Mountain meadows and 

 plains: Ida. Colo. Calif. B.C. Yukon. Plain Mont. Jl-S. 



57. A. Fremontii (T. & G.) A. Gray. Stem 2-4 dm. high; lower leaves petioled, 

 3-10 cm. long, dark green, oblanceolate or spatulate, entire; upper leaves oblong- 

 lanceolate or nearly linear, sessile and somewhat clasping; involucre 7-8 mm. 

 high, about 1 cm. broad; bracts linear, acute or obtusish, the outer wholly green; 

 ligules purple, 7-10 mm. long. Mountain valleys: Alta. Colo. Utah B.C. 

 Mont. Subalp. Jl-Au. 



58. A. Umbachii Rydb. Stem slender, erect, simple, 3-5 dm. high; lower 

 leaves about 1 dm. long, petioled, broadly oblanceolate or lanceolate, dark green, 

 more or less crenate, acute; middle stem-leaves similar but the petioles with 

 dilated, clasping bases; upper stem-leaves lanceolate, sessile; involucres 8-9 mm. 

 high, 12-15 mm. broad; bracts oblong-oblanceolate, acute; ligules dark bluish 

 purple, fully 1 cm. long. River banks: Mont. Mont. Au. 



59. A. ciliomarginatus Rydb. Stem 3-6 dm. high; lower leaves with wing- 

 margined petioles, 1-2 dm. long, oblanceolate, acute; upper leaves lanceolate, 

 sessile, more or less clasping; involucres 8-9 mm. high, 12-15 mm. broad; bracts 

 linear or lance-linear, the outer rarely nearly wholly green; ligules light blue, 10- 

 12 mm. long. A. glastifolius Greene. Along streams: Mont. Colo. Utah 

 B.C. Submont. Mont. Jl-Au. 



60. A. armeriaefolius Greene. Stem 2-3 dm. high, pubescent in lines 

 above; lower leaves petioled, 5-10 cm. long, oblanceolate, entire, acute, deep 

 green, glabrous, reticulate-venose; involucres 6-7 mm. high, about 1 cm. broad; 

 bracts linear or linear-oblong, green or narrowly white-margined below; ligules 

 violet or bluish purple, about 8 mm. long. Mountains: Colo. Wyo. Utah. 

 Mont. Jl-Au. 



61. A. Underwoodii Rydb. Stem 2-3 dm. high, often purplish, more or 

 less hirsute-strigose ; lower leaves spatulate or oblanceolate, tapering into a winged 

 petiole; the other stem-leaves sessile and the uppermost linear-lanceolate; invo- 

 lucres about 8 mm. high and 1 cm. broad; bracts oblanceolate; ligules purple or 

 bluish, about 1 cm. long. High mountains: Colo. Wyo. Mont. Je-S. 



62. A. Tweedyi Rydb. Stem simple, usually purplish, about 4 dm. high; 

 leaves oblanceolate, acute, rather firm, often 1 dm. long, the lower with a winged 

 petiole, the upper sessile and half clasping; heads about 1 cm. high; bracts linear 

 or oblanceolate, not very unequal in length; ligules rose or purple, 8-10 mm. 

 long. Valleys: Colo. Alta. Submont. Jl-Au. 



63. A. adscendens Lindl. Stem ascending or decumbent at the base, 2-8 

 dm. high, glabrous, slightly pubescent above; leaves firm and thick, the lower 

 petioled, 6-12 cm. long, the upper linear, sessile; inflorescence paniculate; invo- 

 lucres 5-6 mm. high, nearly 1 cm. broad; bracts oblanceolate, with green tips; 

 ligules bluish purple, 5-8 mm. long. A. pratincola Greene. (?) A. oxyphyllus 

 Greene. Valleys: Sask. Colo. Nev. Alta. Submont. Mont. Jl-S. 



64. A. Nelsonii Greene. Stem 3-6 dm. high, leafy, sparingly strigose; 

 leaves linear, 5-7 cm. long, firm, entire, acute, 1-nerved; involucres about 8 mm. 

 high, 10 mm. broad; bracts oblong or linear; ligules violet or lilac, 8 mm. long. 

 A. vallicola Greene, a narrow-leaved form. Mountains: Colo. Mont. Wash. 

 Ore. Submont. Jl-S. 



65. A. Nuttallii T. & G. Stem 2-6 dm. high, glabrous or sparingly pubes- 

 cent, especially above; basal leaves linear-oblanceolate, somewhat glaucous, gla- 

 brous; stem-leaves narrowly linear; inflorescence paniculate; involucres 5-6 mm. 

 high, less than 1 cm. broad; bracts oblanceolate, green-tipped; ligules bluish 

 purple, 6-8 mm. long. A. orthophyllus Greene. Mountains: Neb. Colo. 

 Utah. Submont. Jl-Au. 



66. A. halophilus Greene. Stem about 3 dm. high, sparingly hirsutulous- 

 strigose, especially above; stem-leaves linear, 5-8 cm. long, glabrous, except the 



