Onehead Brittlebush

Although Encelia scaposa traditionally has been included within Encelia, it seems misplaced here. Its cypselae differ from those of other encelias in lacking a narrowed apical notch and in having more or less villous (rather than mostly glabrous) faces. Molecular evidence suggests that it may be closer to Flourensia than to members of the alliance comprising Encelia, Enceliopsis, and Geraea.

Perennials, 10–30(–60) cm (caudices 1–2 cm diam.). Stems contracted, at soil surface or ± subterranean (except peduncles). Leaves mostly basal; petioles ± wanting or merging with blades; blades greenish to cinereous, (proximalmost scalelike) mostly narrowly oblanceolate to linear, 30–100 mm (including attenuate bases, mostly 1–8 mm wide), faces ± hirtellous to scabrellous. Heads borne singly. Peduncles ± scabrellous. Involucres 12–22 mm. Phyllaries linear. Ray florets 20–40. Disc corollas yellow, ca. 5 mm. Cypselae (cuneate to obovate) ca. 5 mm (faces ± villous); pappi (readily falling) of 2 (± villous) bristlelike awns.

Simsia scaposa A. Gray, Smithsonian Contr. Knowl. 5(6): 88. 1853; Encelia scaposa var. stenophylla Shinners

Encelia scaposa, common name onehead brittlebush is a North American species of flowering plants in the family Asteraceae. It has been found in western Texas, southwestern New Mexico, and Chihuahua.

Encelia scaposa is a shrub up to 60 cm (2 feet) tall. Leaves are oblanceolate to linear, rarely more than 10 cm (4 inches) long. One plant can produce several flower heads. The heads are unusual in the genus in having as many as 40 ray florets in addition to the disc florets.