192 COMPOSITE. Aster. 



loose and similar. A. adscendens, var. Fremonti, Torr. & Gray, Fl. ii. 503. A. adscendens? 

 partly, Gray, Bot. Calif, i. 324. A. laxifolius, in part, Hook. Lond. Jour. Bot. vi. 160. 

 Rocky Mouiitaius, from Montana to Colorado and Utah, in wet ground below the alpine 

 region, west to the Cascade Mountains, lat. 49, and along the Sierra Nevada, California. 



Var. Parish!!. A dubious form (connecting with the next species '.), with more im- 

 bricated and acute iuvolucral bracts, their margins ciliolate. Bear Valley in the San Ber- 

 uardino Mountains, S. E. California, Parish. 



A. OCCideiltalis, NUTT. A span to a foot or more high, smooth and glabrous (except 

 some minute pubescence below the head), slender; smaller plants simple, bearing solitary 

 or few heads ; larger with slender branches and several or more numerous corymbose or 

 p.-miciilate heads (these 4 or 5 lines high) : leaves mainly linear and narrow; cauliue 1 to 

 3 inches long and only a line or two wide, rarely lanceolate and larger, occasionally (in 

 Nuttall's specimens) bearing one or two salient lateral teeth or lobes ; radical sometimes 

 lanceolate-spatulate with long tapering base : involucre of narrowly or subulate-linear acutish 

 or acute thiuuish loose bracts, obviously imbricated, of 2 or 3 lengths : rays light violet, 

 about 4 lines long. Torr. & Gray, Fl. ii. 164 ( Tripolium occidentals, Nutt. Trans. Am. Phil. 

 Soc. vii, 296), a small and weak alpine form, apparently of a species which at lower eleva- 

 tions becomes taller, rather freely branched, and in Oregon passes into a diffusely much 

 branched and paniculate polycephalous form. Moist grounds and along streams, Idaho to 

 Washington Terr., and along the Sierra Nevada, California, to Kern Co. (..4. astivtts, Roth- 

 rock in Wheeler Rep.) ; first coll. in Oregon by Douglas. 



Var. SCabriusculus. More strict, rather rigid, probably in drier soil with more ex- 

 posure to aridity; stem and leaves scabrous-puberulent. A. testirus, Eaton in Bot. King 

 Exp. 141. Mountains of N. E. Nevada and Utah, Watson, Wood. 



Var. intermedius. Ambiguous between A. occidentalis and a glabrous variety of 

 A , Mcnziesh or of A, adscendens, a foot or two high, rather rigid, somewhat sparingly leafy, 

 with paniculate flowering branches short outer bracts of the involucre often quite obtuse, 

 hut narrower than in the two last-mentioned species : radical and sometimes cauliue leaves 

 lanceolate. Wet meadows, Falcon Valley, &c., Washington Terr., Suksdorf, Howell, Bran- 

 degee, and N. California, Pr ingle. 



2. Tall (3 to 8 feet high) and branching, leafy to the top, paniculately polycephalous: Southwestern. 



A. hesperius. Resembles A. paniculatus and A. salicifolius of the East, equally variable, 

 from nearly glabrous and smooth to scabrous-pubescent . leaves lanceolate, entire or the 

 larger with a few deuticulatious (2 to 5 inches long, 3 to 8 lines wide) : heads rather 

 crowded, 4 or 5 lines high : involucre of narrowly linear or more attenuate acute or gradu- 

 ally acuminate erect bracts, either unequal and imbricated, or with some loose and slender 

 herbaceous exterior ones which equal the inner: rays either white or violet, 3 or 4 lines 

 long. Damp soil and along streams, S. Colorado and New Mexico to Arizona and S. Cali- 

 fornia, Has been variously taken for A. longifolius, Novi-Belgh, astirus, &c., and coll. by 

 Wright, Greene, Rothrock, Cleveland, Parish, Lerumon, &c. 



c. Involucre loose and foliaceous-bracteate at least some of the outer bracts herbaceous or foliaceous 

 to the base or nearly so, equalling the inner, and more or less enlarged, either ascending or 

 squarrose-spreading : the involucre of primary or earlj r heads is more foliaceous; but, when the 

 heads are more numerous, the enlarged outer bracts are not rarely wanting. 



1. Heads small. 



A. Oreganus, NUTT. Nearly glabrous : stem rather slender, 2 feet high, paniculately 

 branched at summit, or bearing several to many paniculate heads ; these about 3 lines high : 

 leaves linear-lanceolate, entire (2 to 4 lines wide) .- outer and herbaceous iuvolucral bracts 

 lanceolate, acute, not longer than the thin and narrow inner ones (in some heads few or 

 none) : rays about 2 lines long, white or purplish. Torr. & Gray, Fl. ii. 163, viz. Tripolium 

 Oni/iuuuii, Nutt. Trans. Am. Phil Soc. vii. 296, on small and hardly developed specimens. 

 A. simplex and perhaps A. carrx us, Eaton in Bot. King Exp. 1. c. A. laxifolius, in part, Hook. 

 Lond Jour. I Jot. vi. 240, not Nees, Wet banks of streams and boggy meadows, Idaho and 

 N. Nc-vada to ( )regou and Washington Terr. : probably also N. California. 



2. Heads middle-sized or large: rayS violet or purple. (Species confluent.) 



A. Douglasii, LINDI, Smooth, glabrous or nearly so : stems 2 or 3 feet high, Avith erect 

 or ascending branches, bearing several or numerous paniculate heads ; these 5 or 6 lines 



