Comprehensive Description
provided by North American Flora
Thymophylla polychaeta (A. Gray) Small, Fl. SE. U. S. 1295
1903.
Hymenatherum polychaelum A. Gray, PI. Wright. 1: 116. 1852. Dyssodia polychaeta B. L. Robinson, Proc. Am. Acad. 49: 508. 1913.
A glabrous annual; stems 1-2 dm. high, branched from the base, with diffuse ascending branches; leaves opposite and alternate, 3-5 cm. long, pinnatifid into 9-13 filiform divisions, with blunt apex and large glands; peduncles 2-6 cm. long; involucre turbinate-hemispheric, without accessory bracts, 5-6 mm. high, about 8 mm. broad; bracts about 16, oblanceolate, with thin membranous short-acuminate apex, carinate at the base and usually with 2 subterminal and 2 lateral glands; ray-flowers about 10; ligules yellow, 5 mm. long, 3 mm. wide,
with 5-7 rather strong nerves; disk-corollas yellow, 3 mm. long; tube shorter than the narrowly
cylindro-funnelform throat; lobes lanceolate; achenes 2.5-3 mm. long, angled, striate, hir-
sutulous on the ribs; pappus 2.5 mm. long; squamcllae 18-20, all awned and some of them
3-awned.
Type locality: Pass of the Limpia, Texas.
Distribution: Western Texas, New Mexico, Chihuahua, Zacatecas, and Coahuila.
- bibliographic citation
- Per Axel Rydberg. 1915. (CARDUALES); CARDUACEAE; HELENIEAE, TAGETEAE. North American flora. vol 34(2). New York Botanical Garden, New York, NY
