Gutierrezia sarothrae, broom snakeweed

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Intermountain Flora
Shrub or subshrub, mostly 2-6 dm tall, commonly dying back partway, often more than halfway, in winter, but only seldom dying back all the way to the branching, woody base; branches of the season numerous, erect, slender, brittle, simple below, branched only toward the summit, herbage mostly scabrous-puberulent; leaves punctate, linear, mostly 2-5 cm long and 1-2 mm wide, sometimes with small axillary fascicles; inflorescence more or less flat-topped, the numerous heads tending to be sessile or subsessile in small glomerules, only rarely many or most of them individually pedunculate and not glomerate; involucre subcylindrical or narrowly obconic, 3-5 (6) mm high and 1-2.5 mm thick, of 8-14 bracts, the outer bracts small, the others larger and broader, mostly 0.8-1.5 mm wide, acutish to broadly rounded distally, with a thickened, sometimes punctate green tip; flowers mostly 5-12 in all, the rays (2) 3-7, 2-3 mm long, the disk-flowers 3-6, all fertile or potentially so; pappus mostly 0.5-1.5 mm long; diploid and tetraploid; 2n = 8, 16.

Cronquist, A., Holmgren, A.H., Holmgren, N.H., Reveal, J.L., and Holmgren, P.K. (1994) "Intermountain Flora" pg.252, vol. 5, The New York Botanical Garden New York.