aster COMPOSITE 807 



17, ASTER Tourn. Inst. 174. L. Gen. n. 954. 



Perennial, or rarely annual herbs with alternate entire or ser- 

 rate leaves and racemose paniculate or corymbose heads of 

 flowers with white, purple or blue ray, and yellow, often chang- 

 ing to purple, disk corollas. Heads many flowered; the ray- 

 flowers in a single series, not very numerous, pistillate ; those of 

 the disk tubular, perfect. Bracts of the involucre more or less im- 

 bricated, usually with herbaceous or foliaceous tips . Receptacle 

 flat or convex, naked. Appendages of the style (in the disk- 

 flowers) lanceolate or subulate, acute, rarely triangular. Pappus 

 simple; of numerous, often unequal, scabrous capillary bristles. 

 Achenes usually compressed. 



* Involucre well imbricated: the bracts appressed and coriaceous 

 with short and abrupt mostly obtuse herbaceous or foliaceous, spread- 

 ing tips: achenes narrow, 5-10-nerved: rays showy, blue or violet: 

 leaves of firm texture, more or less scabrous. 



A. radulinus Gray Proc. Am. Acad, viii, 385. Rough-pubescent 

 throughout: stems rather stout, 6-20 inches high, branching above and 

 bearing an open corymb of middle sized heads: leaves rigid and coriaceous, 

 oblong or the lower obovate-spatulate, sharply serrate above, tapering be- 

 low into a narrow entire base, prominently reticulate-veiny, scabrous both 

 sides, the midrib very prominent beneath: peduncles short: involucre ob- 

 conical, 4-5 lines long, its bracts rigid , appressed, lanceolote or oblong, ob- 

 tuse to abruptly pointed or mucronate, more or less glandular-pubescent, 

 the tips mostly green : rays 15-18, white to purple : achenes minutely pub- 

 escent. Dry open ground, British Columbia to California and Idaho. 



A. conspicuous Lindl. Hook. Fl. ii, 7. Scabrous: stems 1-3 feet high, 

 stout, rigid, bearing several or numerous corymbosely cymose heads, leaves 

 rigid, ovate, oblong, or the lower obovate, acute, ample, often 4-6 inches 

 long, by 1-4 inches broad, acutely serrate, reticulate-venulose as well as 

 veiny: involucre broadly campanulate, about equalling the disk, 5-6 lines 

 high, its bracts in several series, minutely glandular-puberulent or viscidu- 

 lous, lanceolate, acute ; the greenish tips a little spreading : rays half inch 

 long, violet: achenes minutely pubescent. In the mountains of Eastern 

 Washington and Idaho, to British Columbia and the Saskatchewan. 



* * Involucre and usually branchlets viscidly or pruinose-glandular, 

 either well imbricated or loose : rays showy, violet to purple : achenes 

 mostly several-nerved and narrow : pubescence not sericeous : leaves all 

 entire or the lower with few and rare teeth, cauline all sessile or 

 partly clasping. 



A. integrifolius Nutt. Trans. Am. Phil. Soc. n. s.vii, 291. Stems stout, 

 simple 6-12 inches high or more, villous-pubescent, the summit and the 

 simple corymb glandular and viscid : leaves of firm texture, oblong or spat- 

 ulate, or the upper ones lanceolate, the larger ones 4-7 inches long, some- 

 times obsoletely repand-serrulate, apiculate, traversed by a strong midrib- 

 venulose-reticulated, glabrate, half-clasping: lowest tapering into a long 

 stout wing-margined petiole with clasping base : heads fully half inch high, 

 hemispherical: involucre and brancnlets viscid-glandular: its bracts 

 few-ranked, linear, ascending, not squarrose ; the outer sometimes short 

 and rather close, commonly larger and more foliaceous, nearly equalling 

 the inner; these equalling the disk: rays 15-25, bluish-purple, half-inch 

 long : achenes compressed-fusiform, 5-nerved, and sometimes with inter- 

 mediate herves,sparsely pubescent : pappus decidedly rigid. Open and moist 



