Very stout, up to c. 1·5 m. tall. stems deeply furrowed, on stocks ± 3 cm. diam.; bracts with membr. sheaths up to 8 cm. long including blunt ligules, extended into laminae up to c. 8 cm. long with deeply dissected pinnae. Lvs, basal and cauline, on petioles c. 20-30 cm. long; sheaths up to c. 6 cm. long member., with obtuse ligule. Lamina very coriac., 20-25-40 × 20-30 cm., about ovate- to deltoid-oblong in outline. Primary pinnae 6-8 rather distant but overlapping pairs, 10-15 × 5-8 cm. Secondary pinnae ± 3-5 × 1-2 cm.; tertiary up to c. 2 cm. long, deeply to rather shallowly cut into segs ± 5 mm. long tipped by bristle-points. Umbels compound, upper ones approximate, ± 4-6 cm. diam., on stout peduncles up to c. 10 cm. long. Bracts similar to lvs of stem, but smaller. Primary rays stout, unequal, (10)-15-20, ± 2-3 cm. long; involucral bracts few to 0, narrow-lanceolate, ± 1 cm. long. Secondary short, many; involucral bracts linear. Fls c. 4-5 mm. diam.; calyx-lobes minute, bluntly triangular petals white with central brown stripe, ± 2 mm. long, ovate-oblong, subacute with minute hair-process. Fr. 4-5 mm. long, > rays; mericarps deeply 5-3-ribbed, with distinct wings.