194 COMPOSITE. (COMPOSITE FAMILY.) 



only greenish white : akenes puberulent. — Fl. ii. 372. Prairies, Nebraska 

 to Arkansas and Texas, extending westward to within the eastern limits of 

 our range. 

 * * Flowers dull white to yellow : pappus conspicuous, of spatulate or narrow 



scales which have a manifest rib : akenes villous : involucre greener, less peta- 



hid. 



2. H. tenuifolius, Pursh. Lightly tomentose, or soon glabrate and green, 

 leafy : leaves rather rigid, once or twice pinnately parted into very narrowly 

 linear or filiform divisions, their margins soon revolute : heads only 3 or 4 

 lines high, numerous and cymose: involucre rather erect and close; its bracts 

 oblong-obovate, greenish with whitish apex and margins: corolla dull ichite: 

 akenes long-villous. — Fl. ii. 742. Plains, from Nebraska to Arkansas, Texas, 

 and Utah. 



3. H. fllifolius, Hook. Tomentose- canescent, or somewhat denudate and 

 glabrate, nake> above : stems a span to a foot high, sometimes scajjiform : leaves 

 nearly as in the last, or of more filiform rigid divisions: heads a third to half 

 inch high, feiv or solitary : bracts of the involucre oblong or obovate-oblong, 

 largely green or else white-woolly, the tips ivhitish or purplish-tinged : corolla yel- 

 lowish white or sometimes clear yellow: akenes very long-villous. — Probably the 

 H. tenuifolius of Fl. Colorado as well as of Bot. King's Exp. From Nebraska 

 and Montana to New Mexico and S. California. 



52. POLYPTERIS, Nutt. 



Herbs more or less scabrous-pubescent : with undivided and mostly entire 

 petiolate leaves, all or the upper alternate : loosely cymose or paniculate and 

 pedunculate heads of rose-purple flowers. In ours the rays are palmately 

 3-cleft. 



1, P. Hookeriana, Gray. Stout, l to 4 feet high, above glandular- 

 pubescent and somewhat viscid : leaves from narrowly to broadly lanceolate : 

 involucre many-flowered, broad, ^ inch or more high, of 12 to 16 lanceolate 

 bracts in two series, the outer looser and often wholly herbaceous, inner with 

 purplish tips : ray-flowers 8 to 10, the rose-red raj'S ^ inch long, but sometimes 

 reduced or abortive : pappus of the disk of thin scales attenuate at apex into 

 a slender point or short awn, nearly the length of the akene. — Proc. Am. 

 Acad. xix. 30. Sandy plains, from Nebraska to Texas, and extending within 

 the eastern limits of our range. 



63. CH^NACTIS, DC. 



With alternate mostly pinnately dissected leaves, pedunculate solitary or 

 cymose heads of yellow or (in ours) white or flesh-colored flowers, and pappus 

 mostly of entire or merely erose persistent scales (in ours 8 to 14). 



1. C. Douglasii, Hook. & Am. Canescent with a fine somewhat floccose 

 tomentum, or sometimes glabrate, a span to a foot or more high ■ leaves mostly 

 of broad outline and bipinnately parted into crowded short and very obtuse 

 divisions and lobes : heads from ^ to f inch long, in larger plants several or 

 numerous and corymbosely cymose : scales of the pappus from linear-ligulate 



