Citation: L., Sp. Pl. 1007 (1753).

Synonymy: Not Applicable

Common name: Castor oil plant.

Description:
Annual herb or tall branching shrub to 4 m high, glabrous; leaves large, orbicular, up to 60 cm, on petioles 10-30 cm long, palmately divided into 7-9 lobes, lobes lanceolate to ovate-lanceolate, acuminate, irregularly dentate; monoecious.

Flowers in erect loose panicles on thick peduncles to 20 cm long (in S.Aust.); male flowers on pedicels to 10 mm long, several, calyx segments ovate-lanceolate, c. 5 mm long; stamens numerous, to 1000, filaments filiform, anthers 2-celled, globular, c. 0.5 mm long, dehiscing longitudinally, yellow, after anthesis the whole male flower caducous; female flowers with a cleft spathe-like calyx at anthesis, on a filiform pedicel to 5 mm long in fruit extending to 30-50 mm; calyx segments ovate-lanceolate, c. 5 mm long, free, persistent; ovary red, styles 3, usually 2-cleft; ovary and fruit covered with soft spine-like structures.

Capsule ovoid, 8-20 x 10-20 mm, with long conical projections or smooth; seed sub-globular, 9-17 mm, flattened, smooth, shiny, reddish-brown to blackish, marked in various shades of white, grey or brown.

	Ricinus communis twig, male and female flowers, fruit and seed.
Image source: fig 410 in Jessop J.P. & Toelken H.R. (Ed.) 1986. Flora of South Australia (4th edn).

Published illustration: Hegi (1924) Illustrierte Flora von Mittel-Europa 5, 1:fig. 1744; Jessop (1981) Flora of central Australia, fig. 212.

Distribution:  Found commonly in disturbed sites, old fields, along roadsides and channels. S.Aust.: NW, LE, FR, EA, EP, NL, MU, YP, SL, KI, SE.   All States (?Tas.). Conservation status: naturalised Flowering time: in summer (S.Aust.), throughout the year in the tropics.

SA Distribution Map based on current data relating to specimens held in the State Herbarium of South Australia

Biology: Large plants may be tree-like in appearance; the seeds are attractively coloured but are poisonous.

Author: Not yet available