A. WOLFI — A. GRACILIFLORA. 279 



18. ATRIPLEX WOLFI Watson, Proc. Am. Acad. 9:112, 1871. Plate 42. 



Erect annual herb, 1 to 2 dm. high, branched from the base to form an obpyramidal 

 ramose plant; branches ascending or spreading, very slender, tough, scurf y-canescent, 

 glabrate, turning reddish with age; leaves alternate, except 1 or 2 lower pairs, numerous, 

 sessile, linear or the lowest oblong-linear, obtuse or acutish at apex, 0.5 to 1.5 cm. long, 

 0.1 to 0.2 cm. wide, entire, thin, pale gray with a dense fine scurf, 1-nerved, often condu- 

 plicate; flowers monoecious, all axillary, the two kinds mixed in some of the axils but the 

 staminate mostly toward the ends of the branches; perianth of staminate flowers 5-cleft, 

 wanting in the pistillate flowers; fruiting bracts sessile or subsessile, compressed, united 

 to the summit, cuneate-oblong, truncate and with 3 minute teeth at summit, 1.5 to 2 mm. 

 long, about 2 mm. broad, the faces either smooth or with a few minute scattered tubercles, 

 the veins obscured by the scurf; seed 1.5 mm. long, pale brown; radicle superior. 



Southern Wyoming, Colorado, and Utah. Type locality, alkaline flats at Saguache, 

 central Colorado. Collections: Fort Steele, southwestern Wyoming, Tweedy 4495 (NY); 

 type collection, September, 1873, Wolf and Rothrock 277 (Gr, NY) ; North Park, Colorado, 

 August 31, 1897, Osierhout (R); Grand Junction, Colorado, May, 1891, Eastwood (UC); 

 Gunnison, Utah, 1,600 m. altitude, Jones 6525 (US); Circle Valley, Utah, 2,140 m. alti- 

 tude, Jones 5987 (NY, UC, US). Other localities represented by collections in the M. 

 E. Jones Herbarium, Salt Lake City, are Green River, Wyoming; Marysvale, Utah; and 

 Ortons, Utah. 



RELATIONSHIPS. 



Atriplex wolfi is nearest to A. truncata, notwithstanding its very different appearance. 

 The fruiting bracts are almost exact miniatures of some found on this species. Reduc- 

 tion has taken place also in the size and shape of the leaf and in the suppression of the 

 petiole. The dainty habit and the small bracts suggest a connection with the pusilla 

 group, and possibly it represents the beginning of this line. It is unlikely, however, 

 that after a line had once developed the unusual shape of bract so familiar in truncata 

 and in this species, there should be a reversion to the common type found in the Pusillae. 

 Moreover, this group seems to have originated by an entirely different route, namely, 

 through argentea and cordulata, as pointed out under the latter species. Whatever its 

 origin, A. wolfi is now much restricted in its distribution and is not giving rise to new 

 forms. Apparently it is especially adapted to peculiar conditions which it finds only in 

 the easterly part of the Great Basin. It is probably much more common and occurs over 

 a larger area than is indicated by the specimens cited, for the plants are small, delicate, 

 short-lived, and easily overlooked by collectors. 



ECOLOGY AND USES. 

 Atriplex wolfi occurs as a short-lived annual in saline areas, usually in the ^. confertifolia 

 consociation, often forming pure communities, but usually mixed with Salsola, and on 

 lower areas with Suaeda. It is too delicate to be of value for grazing. 



19. ATRIPLEX GRACILIFLORA Jones, Proc. Calif. Acad. II, 5:717, 1895. Plate 42. 

 Erect annual herb, 1 to 3 dm. high, widely branched from the base and also somewhat 

 above, forming a flat-topped or more rounded plant 2 to 6 dm. across; branches curved- 

 ascending, slender, brittle, not angled, .sparsely furfuraceous, early glabrate, the bark 

 then smooth and greenish-white; leaves alternate, except a few of the lowermost, all 

 distinctly petioled, cordate-ovate or deltoid-ovate, cordate or broadly truncate at base, 

 obtuse or acutish at apex, 1 to 2 cm. long exclusive of petiole, 0.8 to 1.6 cm. wide, entire, 

 fleshy but drying thin, greenish, the scurf sparse, the veins evident ; flowers monoecious, 

 the staminate glomerules on short dense branches of terminal panicles, the pistillate all 

 axillary (the plants fructiferous almost from the base); perianth of staminate flowers 



