220 COMPOSITE. (COMPOSITE FAMILY.) 



— Plains of Nebraska and Wyoming to Washington, and south to the moun- 

 tains of Colorado and California. 



78. PRENANTHES, Vaill. 



Perennial herbs, with loosely paniculate heads, few-nerved akenes, and soft 

 bright white pappus. Ours belong to the subgenus Xabalus, with more con- 

 tracted inflorescence, dull-colored flowers, more nerved akenes, and stiffer 

 sordid pappus. 



1. P. racemosa, Michx. Stems simple, 1 to 5 feet high, leafy up to the 

 inflorescence, with the leaves glabrous and glaucous: leaves ordinarily only 

 denticulate ; radical and lower leaves spatulate-oblong to ol)Ovate, tapering into 

 winged petioles ; upper cauline lanceolate to ovate, partly clasping, the broader 

 ones by a cordate or auriculate base : heads not at all drooping, crowded in an 

 elongated thyrsus, a span to 2 feet long : involucre loosely hirsute : flowers pur- 

 plish: akenes about 15-nerved, somewhat angled by 4 or 5 of the stronger 

 nerves. — Xabalus racemosus, DC. From Colorado to the Saskatchewan, 

 thence eastward across the continent. 



2. P. alata, Gray. A foot or two high, the larger plants branching : leaves 

 hastate-deltoid, sharply and irregularly dentate, abruptly contracted or some of the 

 upper cuneately decurrent into winged petioles, or small uppermost narrower 

 and sessile by a tapering base: heads somewhat pendulous, loosely and somewhat 

 corymbosely paniculate: involucre of 8 to 10 greenish bracts : flowers purplish : 

 akenes slender, at least sometimes with a tapering summit. — Synopt. Fl i. 

 435. Xabalus alatus, Hook. From the far north to Oregon, represented in 

 the mountains of N. Mo: tana by 



Var. sagittata, Gray, Leaves sagittate or hastate, with basal lobes 

 mostly slender and prolonged : heads in a virgate panicle : involucre pale 

 green, very glabrous : immature akenes not tapering to the summit. — 

 Loc. cit. 



79. LYGODESMIA, Don. 



Mostlv smooth and glabrous ; with usually rush-like rigid or tough stems, 

 linear or scale-like leaves, and terminal or scattered heads which are always 

 erect : the flowers pink or rose-color. 



* Erect perennials, icith striate-angled junciform stems and branches, and terminal 

 solitary heads: akenes slender, terete, almost fit 'if orm, slightly tapering to sum- 

 mit : pappus soft and copious, whitish or sordid. 



1. L. juncea, Don. Fastigiately much branched from the deep-rooted base, 

 about a foot high : leaves persistent, small, somewhat nervose ; lower lanceo- 

 late-linear from a broadish base, inch or two long : upper reduced to small subu- 

 late scales : involucre at most h inch long, 5-flowered : ligules | or £ inch long. 

 — Plains of the Saskatchewan and Minnesota to New Mexico and Nevada. 



2. L. grandiflora, Torr. & Gray. Stems separate or few from the root, 

 simple beloiv, a span to a foot high ; the larger plants leafy, corymbosely 

 branched above, and bearing few or numerous short-pedunculate heads : leaves 

 all entire, of firm and thickish texture, linear-attenuate, 2 to 4 inches long, only 





