Plants growing scattered along Greene Wash, but commonly along irrigation ditches east of the Sawtooth Mountains, generally below 1600 elevation. 20 cm tall, in variable habitats. Achenes weakly curved and somewhat flattened, 5-7 ribbed, with capillary bristles. Stems leafy, leaves simple, pinnately lobed or merely toothed, diminishing upward, teeth terminating in spines. 30 cm tall, growing at 500-3500' elevation.
Plants scapose, leaves basal, pinnatisect with filiform lobes.
Stems slender, glabrous, leaves mostly basal and diminishing on stem. Heads terminal and axillary, discoid, receptacle conical, corollas greenish. Achenes minute, oblong, obliquely attached, ribbed on inner side, pappus a low, asymmetrical crown. Native, annual herb, growing on sandy or gravelly plains at 1500-5000' elevation. Leaves opposite, linear, with pellucid glands throughout and short bristles near base.