Euphorbia lathyris L.

Glabrous, erect annual to biennial. Stems c. 30–120 cm high, usually not branched at base. Lvs opposite, decussate, exstipulate, sessile, entire, linear to oblong-lanceolate, truncate, acute and often mucronate at apex, 30–150 mm long, glaucous especially when young. Terminal umbel usually 3–4-rayed, with sometimes numerous axillary branches below; lvs subtending rays similar to stem lvs but slightly broader toward base; rays often secondarily branched and then usually forming compound dichasia or developed pseudomonopodially; lvs subtending ray-branches and cyathia broadly triangular, cordate at base. Glands crescent-shaped; horns blunt. Capsule ± smooth or slightly rugose, shallowly grooved, grooved on keels. Seeds rugulose, rounded, brown or grey, c. 5 mm long.

[From: Webb et al. (1988) Flora of New Zealand. Volume 4.]