Forming dense rosettes, stems up to 5 dm. long. Lvs narrowly subflabellately bipinnate. Sheaths rather thin, up to 2 cm. long to division into 2 ligules up to 10 mm. long; stipules irregularly bipinnate, up to c. 2 cm. long. Petioles ± 25 × 5 mm., concavo-convex; internodes ± 25 mm. long. Primary pinnae 3-4 pairs, strongly serrulate-crenulate on midrib and margins, sts again pinnate with lflts up to ± 20 cm. × 3 mm., acicular. Stems stout, grooved, up to c. 10 dm. × 25 mm. including infl. 5-6 dm. long. Bracts ∞, close-set; sheaths up to 7 × 1 cm.; stipules erect, simple to bifid, up to 15 cm. × 1 mm.; central lflt up to 30 cm. long, at length strongly reflexed, margins serrulate. Umbels exceeding the bract-sheaths especially in the male infl. Fr. ± 6 mm. long (not seen in mature state).

2n = 22