C. ALBIDUS — C. PULCHELLUS. 193 



when fully mature, densely villous; pappus copious, exceeding the corolla, white. 

 {Bigelovia albida Jones in Gray, Proc. Am. Acad. 17:209, 1882.) 



A plant of the Great Basin; common only along the westerly side of the Salt Lake 

 Desert; Utah (Wendover to Fish Springs and west, according to Jones), Nevada, and 

 eastern middle California. Type locality, in alkaline soil. Wells, Nevada. Collections: 

 Willow Springs, Utah, May 28 and July 29, 1891, A. J. Jones (Mo. Bot. Card.); Kelton, 

 north end of Great Salt Lake, Utah, Wetmore 466 (US) ; Twin Springs, Nevada, Purpus 

 6SS8 (NY, UC, US); type collection, August 9, 1881, M. E. Jones (Herb. Jones, DS, 

 Gr, NY, UC, US); same locality, Hall 11234 (UC); saline plains of Humboldt County, 

 Nevada, 1865, Torrey 218 (NY); Candelaria, western Nevada, Shockley (DS, NY); 

 Soda Springs and Fish Lake Valley, Esmeralda County, western Nevada, Shockley 554 

 (Gr, NY, US); Owens Valley, eastern California, 1875, Kellogg (Gr). 



RELATIONSHIPS. 



This species is remarkably distinct from all others. The setaceous tips to the 

 involucral bracts early suggested an affinity with C. parryi and the resin-dots are very 

 much like those of the Punctati, but the decidedly cymose inflorescence, the absence of 

 tomentum, and several minor characters indicate that the connection with these is 

 not very close. It seems to stand phylogenetically between parryi and the Typici, 

 approaching the latter perhaps through C. greenei, with which it has much in common. 

 It need not be confused with this latter species, however, for it is a more robust plant 

 with glutinous foliage and larger heads of a distinct aspect. The tips to the bracts are 

 longer and much more curved than in greenei, the flowers are nearly white instead of 

 yellow, and the corolla is fully 2 mm. longer. C. alhidus differs from all other species of 

 Chrysothamnus in the remarkably short anther-tips, and in no other is the stigmatic 

 portion of the style-branch so short in proportion to the appendage. It is this last 

 character especially that renders the species anomalous among the Typici and suggests 

 that it should perhaps be set off in a section by itself. The impressed resin-dots are 

 suggestive of those so highly developed in the section Punctati, but there is no evidence 

 of a direct phylogenetic connection with this group. 



Judging only from the rather scant material thus far collected, C. alhidus is not given 

 to much variation. No segregate species or varieties have been proposed. 



ECOLOGY AND USES. 

 Chrysothamnus albidus is a pronounced halophyte, as indicated by its thickish narrow 

 leaves with revolute margins and resin-dots. In strongly alkaline flats it mixes with 

 C. n. consimilis, Elymus condensatus, and Sarcobatus, but it also invades even more 

 alkaline areas as a pioneer family. Its scarcity precludes commercial use. 



Section III. PULCHELLI. 



8. CHRYSOTHAMNUS PULCHELLUS (Gray) Greene, Erythea 3 : 107, 1895. Plate 29. 



Shrub 3 to 10 dm. high, densely branched at the base; bark of old stems gray or brown; 

 twigs very brittle, short and divergent, leafy, glabrous, striate, the bark at first greenish 

 but soon becoming gray or white; leaves revolute-filiforra to linear-oblong, mucronate, 

 1 to 4 cm. long, 0.5 to 2 mm. wide, l-nerved, green, glabrous or the margins and midrib 

 ciliolate-scabrous (whole surface finely puberulous in one variety); heads several to 

 numerous in each terminal usually lax cyme; involucre 10 to 13 mm. high; bracts 20, 

 25, or 30, in 5 sharply defined vertical ranks, boat-shaped, strongly keeled, attenuate, 

 rigid-chartaceous, more or less greenish toward the apex, glabrous; flowers usually 5; 

 corolla tubular-funnelform, the very slender tube passing gradually into the throat, 

 about 10 to 14 mm. long, glabrous or only granular on the surface; lobes 1.5 to 2 mm. 



