"Affinis ., a qua differt caule valde majore, foliis majoribus, flaccidis, glaucis, vaginis bracteorum multo longioribus et angustioribus, segmentis mediis bracteorum haud reflexis." Lvs (2)-3-pinnate, glaucous or greyish green, flaccid, up to 1·5 m. long; margins serrulate-crenulate, tapering to pungent apex ± 5 mm. long. Sheath up to 2 dm. or more long × 7 cm. at base. Stipules 3-1-foliolate, central lflt stout, 3-10 cm. long with sheaths up to 5 × 2 cm. Petioles ribbed, up to c. 35 cm. × 15 mm., smooth; petiolules up to 10 cm. long; lower internodes ± 5 cm. long. Primary pinnae up to ± 20 cm. × 4-5 mm.; secondary pinnae up to 20 cm. × 4 mm.; terminal lflt up to 45 cm. long (sts not developed). Stems of male plants strongly ribbed, 1·5-2 m. × 7 cm. Infl. up to c. 4 dm. long, narrow-oblong, tapering. Bracts ∞, starting from near base of stem; sheaths yellow, 5-12 cm. × 4 mm.; stipules pinnate to simple, up to 5 cm. long; lamina 3-1-pinnate, of lower bracts up to 4 dm. long, not reflexed. Umbels exceeding bracts, on rather slender peduncles bearing umbellules near base and at apex; involucral bracts linear. Stems of female plants up to 2 m. tall; bracts partly concealing umbels; involucral bracts narrow-lanceolate, ± 8 mm. long; infl. otherwise similar to that of male, but denser.

2n = 22