916 CARDUACEAE 



Bracts of the pistillate heads acute, at least the inner ones. 



Inflorescence and upper leaves filandular-hairy; leaves of the inflorescence 

 large, scarcely smaller than the upper stem-leaves; bracts greenish. 

 Leaves of the stolons 5-1.5 mm. long, rhombic-spatulate; tomentum very 



fine, appressed and silky. 26. A. micropfiylla. 



Leaves of the stolons spatulate, usually roimded at the apex, 1.5-30 mm. 

 long, tomentimi looser. 27. A. bractcosa. 



Inflorescence and upper leaves not glandular, the latter reduced: bracts 

 bro-ivnish. 28. A. oxyphylla. 



VI. Apricae. 

 Plant tall, 2-3 dm. high; heads usually peduncled. 



Leaves less than 2 cm. long and 5-8 mm. wide, usually not triple-nerved; heads 7-9 



mm. high. 28. A. oxyphylla. 



Leaves over 2 cm. long, 7-10 mm. wide, triple-nerved; heads about 1 cm. high. 



29. A. oborata. 

 Plant low, usually less than 1 dm. lugh; heads subsessile. 30. A. aprica. 



VII. C.\MPE3TRES. 



Plantabout 3 dm. Mgh; basal leaves distinctly triple-nerved. 31. A. Howellii. 



Plant 1 dm. or less; basal leaves not distinctly triple-nerved. 



Inflorescence not glandular; bracts of the pistillate heads lanceolate or linear-lanceo- 

 late, acute; those of the staminate heads oblong, obtuse. 32. A. campeslris. 

 Inflorescence more or less glandular-hairy; bracts in both heads ovate to lanceolate, 

 acute or acutish , in the staminate broader. 33. A. marginata. 



VIII. ROSULATAE. 



Bracts with white upper portion; leaves white on both sides. 34. A. rosulata. 



Bracts with brown upper portion; leaves glabrate above. 35. A. Sierrae-Blancae . 



IX. Argenteae. 

 Basal leaves oblanceolate. 36. A. oblanceolata. 



Basal leaves very narrowly Unear-oblanceolate. 37. A. luzuloides. 



X. PULCHERRIM.AE. 



Bracts with a large dark spot, those of the pistillate heads ovate to lanceolate, acute, 

 those of the staminate heads ovate or oval, obtuse or acutish; pistillate heads 

 6-10 mm. liigh, tiu-binate at the base. 

 Plants 1-2 dm. high; ribs of the leaves not conspicuoxis ; outer bracts wholly fuscous. 



38. A. lanata. 

 Plants 3-5 dm. high; leaves with conspicuoiis ribs; tips of the bracts brownish or 

 white. 39. A. pulcherrima. 



Bracts with small dark spots or none; bracts of both staminate and pistillate heads with 

 oblong or oval, obtuse tips, those of the staminate heads slightly broader. 



40. A. anaphaloides. 



XI. DiMORPHAE. 



Plant without filiform stolons. 



Fruiting heads not over 1.5 cm. high; leaves oblanceolate; stem 1-3 cm. high. 



41. A. dimorpha. 

 Fruiting heads about 2 cm. high; leaves spatulate, loosely tomentose; stem 3-5 cm. 



high. 42. A. macrocephala. . 



Plants with flhform ascending stolons. 43. A. flagellaris. 



1. A. racemosa Hook. Stem of the pistillate plant 2-5 dm. high, glabrous 

 or puberulent; leaves of the rosettes 3-ribbed, petioled, 3-7 cm. long, white- 

 tomentose beneath, glabrate above; stem-leaves lanceolate or linear, sessile; 

 heads many; involucres 6-8 mm. high and about as broad; bracts ovate to lanceo- 

 late, acute, light greenish yellow; stem of staminate plant 1-3 dm. high; invo- 

 lucres more hemispheric, 5 mm. high; bracts eUiptic, obtuse, the inner shghtly 

 white-tipped. Woods and hillsides: Alta. — Wyo. — Cahf. — B.C. Submont. — 

 Mont. Je-Au. 



2. A. oblancifolia E. Nels. Stem of the staminate plant 1-2 dm. high; 

 basal leaves oblanceolate, 2-3 cm. long, sparingly tomentose or glabrate above, 

 appressed, white-tomentose beneath; stem-leaves narrowly oblanceolate or 

 linear, acute or acimimate; heads 4-13; involucres 4-5 mm. high, sparsely woolly; 

 bracts oval, obtuse, or roimded, light brownish green below, often with a pur- 

 plish spot and white tips. Wooded slopes: w Wj'o. Mont. Jl. 



3. A. alpina (L.) Gaertn. Stem 5-15 cm. high, floccose; leaves of the 

 stolons siUcy-tomentose, 8-20 mm. long, 2-4 mm. wide; heads usually 3-5, con- 

 glomerate; involucres about 5 mm. high and 8 mm. broad; bracts of the very 

 rare staminate head pale, elliptic, obtuse, those of the pistillate heads dark green- 

 ish brown, lanceolate, long-acvmiinate. Arctic-alpine situations: Greenl. — Lab. 

 —Alta.— B.C.; n Eur. Alp. Jl-Au. 



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