Slender weak diffusely branched annual or winter annual up to ± 10 cm. tall, us. bearing lax spreading hairs. Lvs ± 12-30 mm. long, membr., ± oblong, pinnatisect to bipinnatisect; segs linear, entire, acute, sts apiculate. Scapes very slender; capitula ± 2.5-5 mm. diam.; phyll. in c. 2 series, narrow-oblong, obtuse. Florets white; ♀ ∞, in c. 3 series, on very slender pedicels; disk-florets perfect, very few. Achenes obovoid, glandular, wings thick.

2n = 36

2n = 36

Ascending to erect, slender annual up to 10-(15) cm tall. Stems terete, much-branched from base and above, sparsely to densely clothed in long hairs, up to 20-(40) cm long, not rooting at nodes. Lvs membranous, sparsely to moderately hairy, spathulate, deeply 1-2-pinnatisect, (5)-10-35-(50) mm long; lowermost lvs opposite, petiolate, amplexicaul; lvs above becoming alternate, smaller, apetiolate, and 1-pinnatisect. Involucral bracts in 2 rows, glabrous or with a few scattered hairs, 2-3 mm long. Capitula solitary, pale yellow, 3-5-(6) mm diam.; peduncle sparsely to densely clothed in antrorse hairs, very slightly expanded at apex but solid, (1)-3-6 cm long, 0.5-1 mm diam.; ♀ florets in 2-3 rows, pedicellate, lacking any corolla; ☿ florets (15)-30-40-(50), subsessile, with tubular corolla. Achenes of ♀ florets flattened, 1.2-1.5 × 0.7-1 mm, hairy on both surfaces; lateral angles with thin, glabrous, entire, marginal wings. Achenes of ☿ florets flattened on inner surface, c. 0.9-1.1 × 0.4-0.5 mm, glabrous; lateral angles thinly ribbed.