Ricinus communis L.

Linnaeus, C. (1753), Species Plantarum 2: 1007.  Type: "Habitat in India utraque, Africa, Europa australi."

Palma Christi; Castor Bean; Castor Oil Plant; Jarak

Shrub to 4 m high. Stems glabrous; exudate watery and clear from broken stems and petioles. Stems glaucous becoming streaked with red.

Leaves simple, alternate, young leaves can be dark purple, bronze or green. Stipules intrapetiolar, solitary at each node, encircling the stem, 25-35 mm long, falling early and leaving prominent scars on stem (giving a sheathing appearance to petiole base). Petiole 10-30 cm long (can be up to twice as long as lamina), 2 sessile glands at apex of petiole and 2 or 3 wart-like glands on lower half of petiole, hairless and glaucous. Leaf blade palmately lobed, 10-80 cm long and wide, deeply 7-11-lobed; base peltate, margins finely toothed, apex of lobes acute to acuminate. Both surfaces hairless.

Inflorescences terminal or axillary, paniculate. Flowers unisexual and monoecious, female flowers in upper part of panicle, male flowers in lower part. Male flowers: perianth of 3 -5 tepals, 6-8 mm long, free to base, with numerous stamens in bundles, filaments partially connate and irregularly branched, rudimentary ovary absent, greenish to yellow. Female flowers: perianth of 3-5 tepals, 6-8 mm long, fused in bud, splitting along one suture only (giving spathe-like appearance); 3-lobed superior ovary covered by prickly processes, topped by red plumose stigma, staminodes absent.

Fruit maturing into a dry capsule, ovoid-spherical to depressed-globose, 3-lobed, 10-20 mm diam., green, turning red or brown, prickly, dehiscing explosively. Seeds 3 (1 per lobe/valve), 10-15 mm long, compressed ellipsoid, mottled whitish brown, with small terminal cream caruncle.

Features not available.

An introduced species now naturalised in WA, NT, CYP, NEQ and CEQ, and found throughout Australia. Mainly grows in open communities but also found in clearings and regrowth of subtropical rainforest, dry rainforest and gallery or riparian rainforest.

This profile information and associated coding has been adapted from Green (1994), Harden et al. (2014), and Webster (2014).