BLAKE.— ENCELIA AND RELATED GENERA. 355 
linear-oblong, 2 em. long, 3-4.5 mm. wide; disk-corollas 7 mm. long 
(tube 3 mm.), hairy on teeth and base of tube; pales 13.5 mm. long, 
laterally 1-toothed, glandular-hairy on keel and tip; achene oblong, 
10 mm. long, 3.5 mm. wide, silky-villous on body and margin, awnless 
or with two subulate awns 1.8 mm. long, the squamellae almost com- 
pletely united. 
Tithonia argophylla D. C. Eaton in Wats. Bot. King’s Rep. v. 423 
(1871 
Bncetia See ee argophylla Gray, Proc. Am. Acad. viii. 657 (1873); 
Jones, |. ce. 702 (1895). 
Helianthella argophylla Gray, Proc-Am. Acad. xix. 9 (1883); Co- 
ville, 1. ce. (1893), as to name only. 
Enceliopsis argophylla A. Nels. |. c. (1909). 
Specimens examined: Ura: St. George, 1870, Palmer (fragments 
of TypPE in Gray Herb.); Nevapa: salty cliffs, salt mine near Stone’s 
Ferry, near the Colorado River, alt. 366 m., 11 April 1894, Jones 
5032q (hb. Jones). 
GERAEA Torr. & Gray (yepa:ds old, from the canescent-villous 
achenes). Heads medium-sized or rather large, many-flowered, 
radiate or discoid, the rays neutral; flowers all yellow. Involucre 
hemispheric, the scales 2-3-seriate, linear or broadly oblong, equaling 
or shorter than the disk. Receptacle flattish; pales softly scarious, 
conduplicate, falling with the achenes. Rays when present cuneate, 
the tube hairy; disk-corollas with cylindric tube and broader throat, 
limb hairy and 5-toothed. Style branches long, hairy. Disk-achenes - 
strongly compressed, villous especially on the edges, narrowly cuneate 
with narrow whitish margin produced into two strong awns decurrent 
into the conspicuous crown.— Annuals or biennials (base unknown 
in G. viscida), glandular-pubescent, simple or branched, with alternate 
dentate leaves and usually few paniculate heads. Type species G. 
canescens Torr. & Gray (Encelia eriocephala Gray).— Two species of 
southwestern United States and adjacent Mexico.— The squamella- 
ceous corona of the ovary, from which the thick crown of the fruit is 
at least in part developed, is distinct enough in G. viscida, although 
visible in G. canescens only as a narrow border connecting the decurrent 
based awns. It seems quite analogous with the corona of completely 
fused squamellae in such a species of Enceliopsis as E. nutans. 
Geraea Torr. & Gray, Am. Journ. Sci. ser. 2. iii. 275 (Mar. 1847); 
Proc. Am. Acad. i. 48 (1848). 
