Stems rather stout, 3-6 dm. tall, grooved; stock c. 2-3 cm. diam. Lvs on stout petioles 8-12 cm. long, including sheath narrowed to apex and shortly liguled. Lamina about ovate-oblong, 15-25 × 6-12 cm., 2-3-(4)-pinnate. Primary pinnae 8-12 pairs, 4-8 × 2-3 cm., about obovate, cuneately narrowed to base. Secondary pinnae ± 2-(5) × 0·5-1cm., again pinnate or very deeply cut into linear lobes up to c. 15 × 1-2 mm., with flexuous hair-processes (1)-2-3-(4) mm. long. Stem-bracts or -lvs with sheaths ± 4 × 2 cm. tipped by lamina up to c. 6 cm. long. Umbels us. many, subpaniculately arranged, ± 5-8 cm. diam. Primary rays stout, c. 4-5 cm. long; involucral bracts linear to filiform, hair-tipped. Secondary rays ± 1-2 cm. long; involucral bracts similar, shorter. ♂ with caryx-lobes acute, ± 2 mm. long; ♀ with shorter blunter lobes; petals white, ± 3 mm. long. Fr. (4)-5-(6) mm. long, narrow-ovoid. Mericarps 5-(4)-ribbed and winged. Styles slender, 2-3 mm. long; stylopodia prominent.

2n = 22