Stems creeping, rooting, up to c. 4 dm. long, glab. to silky-hairy; branches very slender to almost filiform, often glab. or nearly so; lvs alt. or fascicled at nodes. Lamina narrowly obovate-oblong, thin, membr., glab. or slightly hairy when young, (10)-15-30-(50) × 5-10 mm.; pinnatisect to pinnate. Pinnae c. 10 pairs, rather distant, subopp.; upper ± oblong, ± 5 × 3 mm., sessile, us. deeply toothed all round, teeth ovate-oblong, acute, apiculate; lower rather distant, c. 2 mm. long, often entire. Costa flat, glab. or sparsely glandular. Petioles chartaceous, 5-(10) mm. long, with sheathing bases. Scape ± 15 mm. long, slender to filiform, nude, with minute sparse hairs. Capitula (2)-3-5 mm. diam.; receptacle slightly convex. Phyll. c. 10, broad-oblong to ovate-oblong, 1-2 mm. long, margins us. purple. Florets and achenes glandular. ♀ in 3-4 series, corolla broad-ovoid, 2-3-toothed or entire; ♂ ∞, funnelform, tube c. 2 mm. long; teeth minute, narrow-triangular. Achenes obovoid, compressed, c. 1 mm. long.

A creeping perennial herb forming open patches. Rhizomes on the soil surface, slender to stout, 0.5-2.0 mm diam.; branches produced earlier in season clustered, up to ca. 5 radiating from around a flowering node; branches produced later in season us. single at flowering nodes. Leaves 3-many clustered at the apex, under better conditions older leaves up to 2 cm apart. Short shoots absent or with 1-few small leaves. Roots ± thick, 0.5-1.0 mm diam. Leaves 1-pinnatifid, 1-5 × 0.3-1.0 cm; blade 0.3-4.0 cm, obovate, coriaceous, dull green, usually with brown pigment on proximal pinnae, ± glabrous; pinnae 5-12 pairs, not overlapping, cut to rhachis, obovate, teeth 0 or up to 7 per pinna, us. restricted to proximal pinnae, on distal margins, cut ½-2/3 across pinna, oblong, obtuse and minutely mucronate. Peduncles borne on rhizomes, equal to or longer than leaves, slender, 2-5 cm, nude or with 1 simple bract, pilose. Monoecious. Heads 4-6 mm diam.; surface convex; involucre outspread; phyllaries 15-20 in 2 equal rows, suborbicular, pilose, with a wide brown scarious margin, not growing after anthesis; pistillate florets 70-130 in 2 or more rows, ca. 1.75 mm long, straight, white; corolla twice as long as wide, with equal teeth; staminate florets ca. equal in number. Achenes ca. 1.0 × 0.5 mm, slightly compressed but almost round in section, pale brown, transversely wrinkled. Chromosome number, n=26. Flowers through the spring and summer and at a reduced rate in autumn and occ. winter.