COMPOSITAE (COMPOSITE FAMILY) 517 



28. Aster Nelsonii Greene, 1. c. Stems slender, wiry, 4-8 dm. high, from 

 branching and only superficially seated subligneous rootstocks, simple, leafy 

 throughout and racemosely or subcorymbosely floriferous above the middle: 

 cauline leaves 5-8 cm. long, firm, narrowly linear, entire, acute, sessile and 

 half-clasping, 1-nerved, glabrous on both faces, the margin scabrellous: in- 

 volucres broadly turbinate, 6-8 mm. high; bracts imbricated in about 3 

 series, the short outermost often wholly herbaceous, oblong and obtuse, the 

 others successively narrower and lanceolate or linear, acute, pubescent on 

 the back and marginally ciliate, mostly well differentiated into lanceolate 

 green tip and marginally colorless linear base: rays about 20, violet or paler, 

 rather narrow and inconspicuous. Frequent on moist banks; Wyoming and 

 Colorado. 



29. Aster adscendens Lindl. Hook. Fl. Bor. Am. 2: 8. 1834. Stem slender, 

 rigid, glabrous or sparingly hirsute-pubescent, branched or simple, 2-5 dm. 

 high: leaves firm, entire, rough-margined, sometimes ciliolate; those of the 

 stem linear-lanceolate or linear-oblong, acute or obtusish, 2-7 cm. long, 

 4-10 mm. wide, sessile by a more or less clasping base; basal leaves spatulate, 

 narrowed into short petioles: heads not numerous, about 25 mm. broad; in- 

 volucre hemispheric; the bracts imbricated in 3-5 series, oblong-linear or 

 spatulate, the tips usually obtuse or obtusish, slightly spreading, the inner 

 often mucronulate: pappus nearly white; achenes pubescent. (A. Nuttallii 

 T. & G.; A. denudatus Nutt.; A. ortfiophyllus Greene, Leaflets 1: 146. 1905; 

 A. pratincola Greene, Pitt. 4: 215. 1900; A. vallicola Greene, 1. c. 213; A. 

 Underwoodii, A. Tweedyi, A. griseolus, A. corymbiformis Rydb. Bull. Torr. 

 Bot. Club 31: 653-5. 1904; A. subracemosus Rydb. Mem. N. Y. Bot. Gard. 

 1: 394. 1900.) Quite variable; throughout our range and northwestward. 



29a. Aster adscendens armeriaefolius (Greene) A. Nels. Resembling the 

 species but the heads usually few; the branches and branchlets slender above 

 and with greatly reduced leaves. (A. armeriaefolius Greene, Pitt. 4: 214. 

 1900.) In the mountains of Colorado. 



30. Aster longifolius Lam. Encycl. 1: 306. 1783. Stems glabrous or some- 

 what pubescent, leafy, paniculately branched, 3-9 dm. high: leaves lanceolate 

 to linear-lanceolate, entire or nearly so, acuminate, narrowed into a sessile, 

 clasping, usually slightly cordate base, 7-20 cm. long, 4-12 mm. wide: heads 

 rather numerous, about 25 mm. broad; involucre hemispheric, 8-10 mm. high; 

 the bracts glabrous, narrow, green, acute, imbricated in only 1 or 2 series, 

 nearly equal: rays numerous, about 8 mm. long, violet or pale purple: pappus 

 pale. (A. lonckophyUus Greene, Leaflets 1: 146. 1905.) Colorado to Mon- 

 tana and thence to New England. 



31. Aster Fremontii T. & G. Gray, Syn. Fl. 1: 191. 1884. Stems slender, 

 erect, 2-5 dm. high, glabrous or the upper parts soft-pubescent: leaves thin- 

 nish, the margins either quite naked and smooth or obscurely ciliolate- 

 scabrous; the radical and lowest cauline oblong or oblanceolate, or somewhat 

 obovate, 3-7 cm. long, tapering into a slender-margined petiole; the cauline 

 oblong-lanceolate to linear, commonly half-clasping at base: heads solitary 

 in the smaller specimens, several in the larger, 8-12 mm. high, somewhat 

 naked-pedunculate; bracts of the involucre narrowly linear, obtuse, or the 

 inner acute, some of the outer shorter, all loose and similar: rays numerous, 

 8-42 mm. long. Wet mountain meadows; in our range and to the north- 

 westward. 



32. Aster Canbyi Vasey, Gray, Syn. Fl. 1: 185. 1884. Stems rather stout, 

 simple or branched above, leafy to the top, 2-6 dm. high: leaves thickish, 

 ample ; the upper cauline mostly oblong, and with broadly, half-clasping, usually 

 auriculate insertion: heads solitary, several or many, large or smaller as the 

 number increases; bracts oblong or spatulate, acute or obtuse, the outer 

 usually shorter, or sometimes more foliaceous and then equaling the disk. 

 [A. Burkei (Gray) Howell, Fl. 310. 1897; A. majusculus Greene, Pitt. 4: 215. 

 1900; A. spathulatus Lindl. (A. subspathulatus Rydb. Mem. N. Y. Bot. Gard. 

 1: 395. 1900); A. ciliomarginatus Rydb. 1. c. 392; A. Cusickii Gray, as to our 

 range.] In the mountains; New Mexico to Montana, Utah, and Washington. 



