200 COMPOSITE. Aster. 



Var. ledophyllus, GRAY. Stem lower (not over 2 feet high), rather strict: leaves 

 smaller (inch or two long), cottony-tomeiitulose beneath, at least when young ; lower obtuse and 

 merely mncrouate, uppermost with slender cuspidate point usually developed. Proc. Am. 

 Acad. viii. 388. A. l(-dv]>h<//lus, Gray, Proc. Am. Acad. xvi. 98, without char. Mount 

 Hood at 4,000 feet and upward, Hall, Howe/1, Mount Paddo (Adams). ^n/cftdwf. Seemingly 

 distinct, but passes into the type and into the following varirt \ . 



Var. glaucescens. 'stem mostly slender, 1 to 3 feet high, in the larger plants 

 more branched above and bearing rather numerous corymbosely disposed heads: leaves 

 somewhat glaucous, win illy glabrous (except the minute ciliolation of the species), lanceo- 

 late, 2 or 3 inches long, 3 to 7 lines wide, uppermost usually attenuate-cuspidate : heads 

 smaller or less broad : involucre of fewer and closer bracts. - - Washington Terr. : on Mount 

 Pail do, and Sincoe Mountains, Saksdorf, Hoicell. N. California, mountains of Siskiyou 

 Co., Green f, Prhnjlf, distributed as A. eleyons, which it approaches. 



A. elegans, TORR. & GRAY. Slender, 1 to 3 feet high, mostly scabro-puberulent : leaves 

 thickish, pale, lanceolate (inch or two long), erect, the upper apiculate-mucronate, the veins 

 inconspicuous : heads several at summit of simple stern or branches, comparatively small 

 and few-flowered (4 or 5 lines high) : involucral bracts all close and conspicuously woolly- 

 eiliate, barely acute, outer ovate, none with pointed tips : rays rather few, about 4 lines long : 

 style-appendages linear-subulate, hardly acute. Fl. ii. 159 ; Eaton, 1. c. (a somewhat ambig- 

 uous form). Bucephalus t%"-S ^'utt. Trans. Am. Phil. Sue. vii. 298.- - Mountains of 

 Wyoming and Montana to N. Nevada and E. Oregon ; first coll. by Xnttiill. 



-l_ -i__ Style-appendages obtuse and short-oblong, shorter than the stigmatic portion: involucral 

 bracts fir.r.er; all the outer obtuse, not ciliate nor scarious-margined : akenes narrower, merely 

 pubescent. 



A. glaucus, TORR. & GRAY. Throughout smooth and glabrous, glaucescent or pale : stems 

 a foot high from extensively creeping filiform rootstocks, branching, bearing several or 

 numerous paniculate heads : leaves thickish, lanceolate (1 to 3 inch.es long, a quarter to half 

 inch broad), rather obtuse, when dry reticulate-vcnulose both sides: involucre 3 lines high, 

 imbricated in about 3 ranks: rays bright violet, 4 to G lines long. Fl. ii. 150; Eaton, 1. c. 

 Kii<;"lilt<i/nx (/.it'/nU-ii) glaucus, Nutt. I.e. Rocky Mountains, Wyoming to Colorado and 

 Utah. 



* * * * Involucre less imbricated, hemispherical; the bracts in few ranks and in the typical 

 species somewhat equal, partly greenish, with or without scarious margins: pappus-bristles not 

 clavellate-thickened at tip : lu\v-steimued or acaulescent, from a thick and sometimes ligneous 

 caiulex or rootstock, with solitary or few pedunculate heads, and rather large and numerous 

 rays: leave-; thickish, narrow, one-nerved or nervose, entire. XylorrJiiza, Nutt. Trans. Am. 

 I'liil. Soc. vii. 2J8. Orthomeri*, Xy/orrltiza, Ton-. & Gray, 1. c. : also Benth. & Hook. Gen. 

 i!. 27-i. exel. syn. Uliii/'irllna (which has a double pappus) & Arctoyeron (which lias the char- 

 acters of Krtyeron with somewhat too imbricated involucre), We-i'-m montane species. 



-1 Genuine species, with comparatively large (half-inch high or more) and showy heads, and 

 thickish leaves : pappus-bristles, rather rigid. 



-H- Heads terminating short leafy stems which arise from creeping and ligneous rootstocks: invo- 

 lucral bracts acuminate and mucronate-tipped : style-appendages triangular- or lanceolate-subu- 

 late, not attenuate, shorter than the stigmatic portion : akenes oblong, very villous. Xylorrlti-<i, 

 Nutt. 



A. Parryi, GRAY. Tomentose-pubescent and cinereous, a span high : leaves mostly spatulate 

 and obt.use with a mucronate point, an inch or more long : heads usually solitary on peduncle 

 surpassing the leaves, very broad: bracts of the involucre oblong-lanceolate, densely cine- 

 reous-pubescent : rays white, over half-inch long. Am. Nat. viii. 212. Rocky Mountains 

 in Wyoming, on marshy flats of Sandy Creek, Green River, &c., Parry, A. J. A/cCWi. 



A. Xylorrhiza, TORR. & GRAY. Less pubescent and glabrate, 4 to 8 inches high : leaves 

 from narrowly spatulate-laticeolate to linear (1 or 2 inches long, 1 to 3 lines wide) ; the upper 

 commonly equalling the 1 to 3 peduncles: heads smaller: involucral bracts more attenuate: 

 rays "pale red" or "pale rose-color," 4 lines long. Xylorrhiza villosa & X. glabriuscvla, 

 Nutt. Trans. Am. Phil. Soc. n. ser. vii. 297, 298. Aster Xylorrhiza & A. glabriusculus, Torr. 

 & Gray, 1. c. 158 ; the latter a more leafy-stemmed form. Clayey soil and on rocks, Rocky 

 Mountains of Wyoming, toward the sources of the Platte ; first coll. by Nuttall. Laramie 

 Plains, Parry. 



