Xanthisma spinulosum var. glaberrimum (Rydb.) D.R.Morgan & R.L.Hartm. (redirected from: Sideranthus glaberrimus)
Family: Asteraceae
[Haplopappus spinulosus subsp. glaberrimus (Rydb.) H.M.Hall,  more...]
Images
not available

Perennials, 20-50 cm, often woody at base. Stems stiffly erect, branched in distal 1 / 3 ; mid internodes 2-5 mm. Leaves numerous, strictly ascending, not reduced distally, margins pinnatifid, lobes oblong-lanceolate to triangular, 2-7 mm, faces usually glabrous, sometimes lightly tomentose, eglandular. Heads 2-10+, (subsesssile) usually clustered. Peduncles relatively terminal and lateral, 0.5-2 cm. Involucres 8-15 mm wide. 2n = 8, 16.

Flowering spring-fall. Sandy to gravelly prairies, hillsides, and roadsides; 800-1400 m; Colo., Iowa, Kan., Nebr., N.Mex., N.Dak., Okla., Tex., Wyo.

G. L. Nesom (2003) recognized Xanthisma spinulosum var. glaberrium at species level, as it occurs sympatrically with variety spinulosum in the Texas panhandle, where the two taxa behave like biological species; on the eastern plains of Colorado, however, hybridization and autoploidy have been documented (D. P. Hauber 1986).