FLOWERING PLANTS AND FERNS OF ARIZONA 959 



66. GERAEA. » Desert-sunflower 



Annual herb, hirsute, branching; leaves alternate, oblong, ovate, 

 or obovate. toothed; heads Large, showy, yellow, radiate; phyllaries 

 conspicuously white-ciliate; achenes cuneate, strongly compressed, 

 silky-villous, the body black, the narrow whitish margin continuous 

 with the 2 strong awns, these connected by a low entire whitish crown. 



1. Geraea canescens Torr. and Grav, Amer. Jour. Sci. ser. 2, 3: 275. 



1847. 



Enedia eriocepkala A. Grav. Amer. Acad. Arts and Sci. Proc. 8: 

 657. 1873. 



Mohave, Maricopa. Pinal, western Pima, and Yuma Counties. 

 1 .500 feet or lower, common in sandy soil, January to June. Southern 

 Utah to southeastern California, western and southern Arizona, 

 and Sonora. 



The var. panicvlata (A. Gray) Blake (Encelia eriocephala var. 

 pani culata A. Gray), is an unimportant form with stems paniculately 

 much-branched above, bearing very numerous heads only 2 to 2.8 

 cm. wide, known only from the type collection, at Phoenix (Pringle 

 in 1882). 



67. ENCELIOPSIS 83 



Scapose perennial herb, silvery-velutinous ; leaves obovate, entire, 

 in a basal tuft; heads solitary, large, yellow, radiate, on naked scapes; 

 achenes oblong, strongly compressed, silky-villous, black, with a white 

 cartilaginous border and crown; pappus of 2 short awns, or none. 



1. Enceliopsis argophylla (D. C. Eaton) A. Xels., Bot. Gaz. 47: 433. 

 1909. 



Tithonia argophylla D. C. Eaton in King, Geol. Expl. 40th Par. 

 5: 423. 1871. 



Xavajo Bridge, Coconino County (Peebles and Parker 14654), 

 Mohave Countv. at Virgin Narrows (Cottarn 5131) and near Boulder 

 Dam {Kearney and Peebles 11239), 1,000 to 3,700 feet, dry slopes and 

 sandy washes, April to June. Southern Utah, southern Nevada, and 

 northwestern Arizona. 



The record of Enceliopsis nudicavlis (A. Gray) A. Xels. from Arizona 84 was 

 based on a specimen without heads, so labeled, in the National Herbarium (Jones 

 5095ak, from above Pagumpa Springs, 1894), which on more careful examination 

 is found to be Gaillardia parry i Greene. 



08. HELIAXTHELLA 



Perennial herbs; leaves opposite or alternate, lanceolate to ovate, 

 entire; heads radiate, medium-sized or large, with yellow rays and a 

 yellow or purple disk; achenes strongly compressed, obovate, not 

 filiate; pappus of fimbriate squamellae and often 2 slender awns. 



■-' Reference: Blake, S. F. a revision of encelia and some allied genera. Amer. Acad. Arts and 



Sci. Proc. 49 (Gray Herbarium Contrib. 41): 355-357. 1913. 

 i; Reference: Blake. S. F. a revision of encelia and some allied genera. Amer. Acad. Arts and 



Sci. Proc. 49 (Gray Herbarium Contrib. 41): 351-355. 1913. 

 " Blake. S. P., Asteraceae, in Tidestrom, Ivar. flora of UTAH and Nevada. Contrib. U. S. Natl. 



Herbarium 25: 1925. (See p. 586.) 



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