Stems creeping, rooting, branched, ± clad in ascending hairs; lvs alt., often tufted at nodes. Lamina membr., gland-dotted, obovate to narrow-obovate, glab. or nearly so, (2)-4-5-(8) × 1-2 cm.; lower part pinnatisect, upper pinnatifid; pinnae ± irregularly crenately to serrately toothed, ± 15 mm. long, uppermost close-set, subentire. Petioles 2-5 cm. long, flat; bases expanded, semiamplexicaul. Scape axillary, ± 5-8 cm. long, nude, ± pubescent. Capitula 8-10 mm. diam.; receptacle convex. Phyll. ± 30 in 2-3 series, broad-ovate to ovate-oblong, subacute to obtuse, sparsely hairy. Florets eglandular; ♀ in c. 3 series with ovoid corolla, style-arms very short; ♂ tubular, 4-toothed, style undivided. Achenes slightly glandular, ± clavate, tetragonous, narrowly winged.

A diffusely creeping perennial herb. Rhizomes on soil surface, rather thick, pale, sparsely pilose; branches usually single at flowering nodes; leaves in two rows, single at apex, 0.5-4.0 cm apart. Short shoots alternate on both sides of the rhizome, with clustered leaves, sts converted into rhizomes with distant leaves. Roots slender and weak, up to 0.5 mm diam. Leaves 1-pinnatifid, 2-12 × 0.4-2.5 cm; blade 1-8 cm, obovate, subfleshy, yellow-green, without brown pigment, glabrous or almost so, midrib slightly raised on proximal part of ventral surface: pinnae 6-15 pairs, not overlapping, cut to rhachis or distalmost sinuses not quite reaching rhachis in larger leaves, elliptic; teeth on most pinnae, up to 12 per pinna, almost equally on distal and proximal margins, cut ca. ¼ across pinna, triangular, obtuse or acute, occ. themselves with 1-2 teeth. Peduncles us. borne on rhizomes, us. longer than leaves, 2-7 cm, nude or with 1 simple bract, sparsely pilose. Monoecious. Heads 5-8 mm diam., surface hemispherical to steeply convex; involucre flat or spreading; phyllaries 15-30 in 2 or more subequal rows, elliptic to oblong, green, almost glabrous, with a narrow transparent scarious margin, not growing after anthesis; pistillate florets 60-200 in 4-6 rows, ca. 2.0 mm long, slightly curved, yellow-green; corolla slightly longer than wide, with unequal teeth; staminate florets more numerous. Achenes up to 1.5 × 0.8 mm, slightly compressed, almost round or irregularly angled, with a pale unwrinkled papery surface turning brown and smooth. Flowers in spring and summer.