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BLAKE.— ENCELIA AND RELATED GENERA. 375 
THorIpeESs HBK. The ray-flowers are described as neutral by Brande- 
gee, but in the specimens of the type collection examined are styliferous 
but undoubtedly sterile. 
Encelia nivea Benth. Bot. Voy. Sulph. 27 (1844) has been variously 
identified, but from the opposite leaves and the thickened achenes 
cannot have been an Encelia, and was probably a Viguwiera. 
Encelia oblonga Rob. & Fern. Proc. Am. Acad. xxx. 118 (1894), from 
Durango and Chihuahua, is a synonym of Helianthella Pringlei Gray, 
Proc. Am. Acad. xxi. 389 (1886). The species, an alternate-leaved 
frutescent plant with large heads solitary and long-peduncled at tips 
of stems, and involucre of ovate-based long-attenuate somewhat 
foliaceous bracts much exceeding the slightly resinous disk, is some- 
what anomalous in appearance, but seems best referred to Flowrensia 
as F. Pringlei (Gray) Blake, n. comb. The achenes are oblong, 
11 mm. long, much thickened, striate, densely pubescent, and tend 
at maturity to lose the 2 awns which compose the pappus. 
Encelia pilosa Greenm. |. c. xxxix. 111 (1903) is a synonym of 
IMSIA LAGASCAEFORMIS DC. 
Encelia pleistocephala J. D. Sm. Bot. Gaz. xiii. 189 (1888) = VER- 
BESINA PLEISTOCEPHALA (J. D. Sm.) Rob. Proc. Am. Acad. xliii. 41 
Encelia polycephala Hemsl. |. ec. 184 (1881) is a synonym of SrMsta 
POLYCEPHALA Benth. 
Encelia Pringlei Fern. Proc. Am. Acad. xxxv. 573 (1900), from 
Hidalgo, has the pappus and achene of Viguiera and should be referred 
to that genus as VIGUIERA trachyphylla Blake, n. nom. (not V. 
Pringlet Rob. & Greenm. Proc. Am. Acad. xxix. 387 (1894). 
Encelia purpurea Rose, Contr. U. S. Nat. Herb. i. 336 (1895) = 
TMSIA LAGASCAEFORMIS DC. 
Encelia resinosa Brandeg. Zoe v. 240 (1906), from Hidalgo, an 
alternate-leaved resinous shrub with a few racemose axillary large 
heads, seems best referred to Flourensia as F. resinosa (Brandeg.) 
Blake, n.comb. The young achene is flattish, scantily haired on the 
sides and thickly at the apex, with two long awns disposed to be 
trifid from near the base. 
Encelia rhombifolia Rob. & Greenm. Am. Journ. Sci. ser. 3. 1. 155 
(1895), from Oaxaca = Vicurera rhombifolia (Rob. & Greenm.) 
Blake, n. comb. Pappus of two awns with intermediate short squamel- 
lae; achene thickened and pubescent. 
Encelia sanguinea Hemsl. |. c. 185 (1881) = Smmsta SANGUINEA Gray. 
Encelia sericea Hemsl. |. ¢. 185 (1881) is a Simsia. 
Encelia Sodiroi Hieron. Bot. Jahrb. xxix. 43 (1900) is a Simsza. 
