Castor Oil Plant

Castor Oil Plant – Ricinus communis

Habit: Shrub with glossy red to green leaves. Male yellow flowers and red female flowers on the same stalk.

Spread: Poisonous seeds are spread in water and on muddy tyres.

The seeds of castor oil plant are enclosed within a spiny capsule. Incredibly, they contain “castor oil” (!) which is processed in places like India, China and Brazil. The seeds themselves contain a toxin called ricin which is very poisonous!  New leaves are a glossy red-green and becoming green when mature. The leaves are distinctive, with 5-9 lobes and jagged edges.

(Photo: Louise Williams)

Castor oil plant is often found in old rubbish tips. It can reportedly grow to 3-5m, however the plants pictured above were only 1-2m.  At this site, plants were emerging from an old tin can dump outside Bidyadanga. The plants are easily removed by hand-pulling when the soil (or rubbish) is soft.  There is lots of castor oil plant in Queensland and not much in the Kimberley so far. Seeds can be easily spread by floodwater’s and through moved soil, so there is a need to quickly get on top of this plant to restrict it’s spread.

(Photo: Louise Williams)

The castor oil plant has separate male and female flowers on the end of the flower stalk. The female flowers are red and the male flowers are yellow.

(Photo: Louise Williams)