220 COMPOSITE. (COMPOSITE FAMILY.) 



Plains of Nebraska and Wyoming to Washington Territory, and south to 

 the mountains 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 Nabalus, 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 obovate, 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: akeues about 15-nerved, somewhat angled by 4 or 5 of the stronger 

 nerves. Nabalus 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 tbe 

 upper cuneately decurrent into winged petioles, or small uppermost narrower 

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

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

 akenes slender, at lea?t sometimes with a tapering summit. Synopt. Fl. i. 

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

 the mountains of N. Montana 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. 



Mostly 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, with striate-angfed junciform stems and branches, and terminal 

 solitary heads: akenes slender, terete, almost filiform, slightly taper inq to sum- 

 mit : pappus soft and copious, whitish or sordid. 



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

 about afoot high: leaves persistent, small, somewhat nervose; lower lancfo- 

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

 late scales : involucre at most ^ inch long, 5-flowered : ligules j 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 below, a span to a foot high ; tbe 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 



