Hemicryptophyte (biennial or rarely perennial). Slightly foetid plant, to 120 cm; tap­root carrot-shaped, 30–40 × 15–17 mm. Stem solid, straight, with the primary umbel at the top and most branches in the upper part; basal part 4–6 mm thick, angular, straw-coloured, ± glaucous; upper internodes with three distinct, glabrous or ciliate wings (decurrent from the mid-vein and edges of next leaf). Leaves 4–6 at the base (usually withered at anthesis) and 8–9 on the stem, one of the lower stem leaves largest. Lower leaves with a rather broad, straw-coloured sheath; petiole 7.5–11 cm; blade 1–2-pinnate, 7.5–11 × 7–10 cm (length/width ratio 1.1–1.2). Primary leaflets 1–3 pairs; angle leaflet/rachis 40–45°. Ultimate leaflets entire or with one pair of lobes; petiolule 12–19 mm; blade ovate to broadly elliptic, 30–40 × 30–40 mm (length/width ratio 0.9–1.3); margin serrate in upper part; base cordate; apex acute or obtuse. Upper leaves stem-clasping; blade entire, ovate to almost triangular, 7–17 × 3.5–10 cm (length/width ratio 1.4–2); margin serrate; apex mostly obtuse.

Distribution and habitat. Grown for ornament, e.g. in parks and botanic gardens, and escaped; increasing at some localities. – D Sjæ scattered in the København area (earliest record Frederiksberg 1924), rare elsewhere, Brn Ypnested (deciduous woodland) since 1983, Gudhjem since 1991. S Sk Lomma (Alnarp, park) since 1919, Lund (botanical garden) since at least 1970, in both places numerous and established; Sövestad (Krageholm, park) 1929–32, probably vanished, Svedala 1987 (small stand in former plantation), Revinge 2008, SmI Östra Torsås 1992 (shrubbery), Upl Kista 2000–02, 2008 (ruderal ground).