Slender, rather flaccid herb up to c. 3 dm. tall; lvs simple to trifoliolate to pinnate or bipinnate, up to 2 dm. long. Sheaths thin, ± 6 cm. × (4)-8 mm.; stipules 0 or unequal, filiform, up to 2 cm. long. Petioles very slender, up to c. 4 cm. long; internodes 0 or up to 25 mm. long. Primary pinnae occ. bipinnately divided near base, 2-4 distant pairs up to c. 7·5 cm. × 1-1·5 mm., pungent, margins minutely crenulate; ultimate segs up to c. 3 cm. × 1·5 mm. Stems of male plants up to c. 3 dm., sts ± lfy near base; infl. lax, up to ± 20 cm. long. Bracts ∞, lowest with compound lamina, upper with minute stipules and simple lamina; sheaths broad, up to c. 5 cm. long; stipules acicular, very slender, lower c. 10 mm. long; lower laminae on slender petioles up to 3 cm. long, with 1 pair of pinnae, or outer member or both absent. Umbels ∞, lowest on peduncles up to c. 5 cm. long; umbellules ± 5 mm. diam., on filiform rays up to 10 mm. long. Stems of female plants ± lfy near base. Bracts ∞, rather rigid, as in male plants. Umbels fewer than in male plants, on short erect peduncles, ± concealed by bracts. Fr. 3-5 mm. long; mericarps 5-3-winged.