342 COMPOSITE HBLIANTHCTS 



H. Donglasii T. & G. 1. c. Stems hirsute with spreading hairs, at least 

 above, 1-4 feet high, striate-angled, leafy : leaves oblong-lanceolate, acutish, 

 nearly sessile, triple-nerved, rough-pubescent, 2-4 inches long: bracts of 

 the involucre linear-lanceolate to subulate, 6-9 lines long : rays an inch long : 

 disk nearly an inch broad : achenes obovate, more or less ciliate, fringed : 

 pappus a pair of elongated awns with more or leas chaffy dilated base, or 

 sometimes reduced to this base, and with mostly conspicuous squamellse. 

 Dry grounds, eastern Oregon to British Columbia. 



43 HELIANTHUS L. Gen. n. 979.- [sunflower.] 



Erect annual or perennial herbs with simple leaves and large 

 heads of yellow flowers, or those of the disk sometimes brown 

 or purple. Involucre hemispherical or deprt ssed ; its bracts 

 imbricateb in several series. Receptacle flat to conic, chaffy ; 

 the chaff subtending and more or less embracing the achenes. 

 Ray-flowers neutral: those of the disk perfect and fertile, with 

 short proper tube and 5-toothed limb. Anthers entire or min- 

 utely 2-toothed at the base. Style-branches tipped with hir- 

 sute appendages. Achenes thick, oblong or obovate, compressed 

 or somewhat 4-angled. Pappus of 2 scales or awns, or sometimes 

 with 2-4 additional ones, deciduous. 



§ 1 Annuals. Involucre spreading, its bracts attenuate to a 

 point. Disk-flowers brownish or dark purple. Receqtacle flat 

 or nearly so. Leaves petioled, 3-ribbed from or near the base, 

 all but the lower usually alternate. 



H. annnns li. Sp. if, 904. Stems hispid or scabrous, stout, branched 

 above, 2-6 feet high, or in cultivated forms sometimes 15 feet high: leaves 

 all but the lowest alternate, broadly ovate, petioled, 3-nerved, dentate or 

 denticulate, acute at the apex, rough on both sides, sometimes pubescent 

 beneath , cordate at base, 2-12 inches long : bracts of the involucre hispid and 

 hispid-ciliate, the outer ovate and abruptly attenuate to a stout bristle, the 

 inner lanceolate and attenuate : rays lanceolate, 1-2 inches long: disk an 

 inch or more or in cultivated plants 4-10 inches in diameter: chaff of the re- 

 ceptacle 3-cleft: achenes obovate-oblong, appressed-pubescent to nearly gla- 

 brous. Oo sandy banks and plains. Brit. Columbia to California and Minn. 



H. petiolaris Nutt. Joum. Acad. Philad. ii, 115. Stems strigose-hispdi 

 or hirsute, 1-3 feet high , simple or branched : leaves all but the lowest alter- 

 nate, petioled, oblong or ovate to lanceolate, rough on both sides, usually 

 paler beneath, 1-3 inches long, entire or denticulate, mostly narrowed at 

 the base to a long and slender petiole : bracts of the involucre lanceolate or 

 oblong-lanceolate, with acute and mucronate or sometimes more attenuate 

 tips, seldom at all ciliate: rays oblong, 12-18 lines'long : disk 6-10 lines in 

 diameter: chaff of the receptacle 3 toothed, not longer than the corollas: 

 achenes villous-pubescent. On dry prairies, Washington to Arizona, Min- 

 nesota and the Northwest Territory. 



H. exilis Gray Proc. Am. Acad, vi, 545, More or less hirsute : stems 

 slender, 1-2 feet high, branching: leaves linear-oblong or lanceolate, nearly 

 entire, obscurely 3-nerved at base, tapering into a short petiole: heads small, 

 on slender sometimes leafy-bracted peduncles: involucre loosely hirsute, its 

 bracts linear-lanceolate,attenuate-acuminate: rays 5-8: chaff of the receptacle 

 produced into an awn-like cusp which equals or surpasses the dark-purple 

 corollas: achenes nearly glabrous : pappus of 2 ovate-lanceolate chaffy scale, 



