Hymenopappus. COMPOSITE. 335 



102, & PI. Wright, ii. 97 ; Eothrock in Wheeler Rep. vi. 168. Elver-bottoms, &c., S. Arizona 

 and New Mexico; first coll. by Wislizenus. (Adj. Mex.) 



H. W^rightii, GRAY. Leaves with very narrow linear or almost filiform divisions, the 

 lower cauline hirsute : heads broader : involucre of obovate-oblong and very obtuse purple- 

 tinged bracts, and a few smaller narrow accessory ones : rays none : disk-corollas white or 

 purplish, 5-parted almost down to the narrow tube into oblong-linear widely spreading lobes : 

 style-tips with a slender-subulate cusp : akenes broader, villous : pappus of broader paleaj 

 and smoother awned tips. PI. Wright, ii. 97; Torr. iu Sitgreaves Rep. t. 6; Rothrock, 

 1. c. Along streams, S. Arizona, Wright, Thurber, &c. (Lower California, Orcutt.) 



148. HYMENOPAPPUS, L'Her. (From v^v, membrane, 7^?, 

 pappus, the latter of hyaline palese.) North American and North Mexican 

 herbs (chiefly of the prairies and plains), perennial, biennial, or some perhaps 

 winter annuals, mostly floccose-tomentose and with sulcate-angled erect stems, 

 alternate 1-2-pinnatifid or parted leaves, the lower sometimes entire, and corym- 

 bosely cyniose or solitary pedunculate middle-sized heads of white or yellow 

 flowers. Leaves in some species evidently impressed-punctate. When the corolla 

 is deeply cleft the nerves of its lobes are deeply intramarginal. Fl. spring. 

 "L'Her. Diss. cum icon."; Michx. Fl. ii. 103; Cass. Diet. Iv. 266, 279; DC. 

 Prodr. v. 658 ; Gray, Proc. Am. Acad. xix. 29. 



* Lobes of the white corolla as long as the short -campanulate or crateriform throat; the tube long 

 and slender, much exceeding the short pappus : stamens with even the filaments mostly exserted : 

 akenes merely pubescent, clavate-obpyramidal, with much thickened summit and stipitiform 

 base: involucre of comparatively lax and partly white-petaloid bracts: heads corymbiform- 

 cymose and rather numerous, on short peduncles: comparatively Eastern species, biennials, 

 1 to 3 feet high. 



-s Pappus of very small obovate or roundish nerveless paleae forming a crown, much shorter than 

 the breadth of the summit of the merely pubescent akeue, often minute, even obsolete: floccoso 

 or pannose tomentum thin, sometimes deciduous. 



H. SCabiosa3US, L'llER. Leafy to the top, thinly tomentose : radical leaves pinnately 

 parted or occasionally entire, cauline irregularly 1-2-pinnately parted into broadly or nar- 

 rowly linear lobes : heads about 5 lines high : the broad involucre somewhat radiate-expanded, 

 its mainly white bracts roundish-obovate, at first surpassing the disk : akeues short-pubescent. 

 Michx. Fl. ii. 104; Torr. Gray, Fl. ii. 372. Rotkiu Carolinensis, Lam. Jour. Hist. Nat. 

 i. 16, t. 1, & 111. t. 667. Sandy pine-barrens, Middle Florida to S. Carolina, and west to 

 Illinois and Texas. 



H. COrymbosUS, TORR. GRAY. More slender, smaller, and glabrate, naked above : 

 lower leaves 2-pmnately and the small upper ones mostly simply parted into narrowly linear 

 acute divisions and lobes : heads 3 or 4 lines high : bracts of the involucre much smaller, 

 shorter than the flowers, obovate-oblong, the petaloid summit only greenish-white : akenes 

 puberulent. Fl. ii. 372. Prairies, Nebraska to Arkansas and Texas. The var. Nuttallii, 

 ' Torr. Gray, as to plant in herb. Torr., belongs here, but the //. tenuifolius of Nuttall in 

 other herbaria is Pursh's species. 



-1 -i Pappus of larger spatulate-obovate paleae, in length nearly equalling the breadth of the 

 summit of the villous-pubescent akene, partly traversed by a callous-thickened axis or obscure 

 costa. 



H. artemisisefolius, DC. Pannosely or somewhat floccosely white-tomentose, or some- 

 what denudate in age : leaves from simply pinnatifid or lyrately few-lobed, and sometimes 

 quite entire (lanceolate or oblong), to bipinnately parted into broadly linear or narrowly 

 oblong obtuse divisions and lobes : heads 4 lines high : bracts of the involucre obovate- 

 oblong, about equalling the disk-flowers, dull white, lower half green. Prodr. v. 658 ; Torr. 

 Gray, Fl. ii. 372. Texas; first coll. by Berlandier. 



* * Lobes of the corolla more or less shorter than the throat: pappus conspicuous, of spat u late or 

 narrow palese, which have a manifest costa or thicker opaque axis, this evanescent near or below 

 the obtuse or retuse apex: akenes villous: involucre greener, less petaloid. 



