Castor bean is a hardy plant that grows into small trees in disturbed sites from the peninsula to the central and western panhandle (Wunderlin, 2003). It is reported in 24 states from California to Michigan to New Hampshire and throughout the southeastern U.S. (Kartesz 1999). It is native to Africa and blooms from summer to fall.
Many-branched; annual or perennial shrub, tree or herb, 1–5 m (3.3–16.5 ft) tall.
Alternate, simple, coarse, to 40 cm (15.5 in) wide; 7–9 coarsely serrate palmate lobes, with long petiole attached near center of lower leaf surface.
Conspicuous, upright spikes; sepals 5, petals 0; male flowers yellow; female flowers pink to pinkish red; appearing nearly year-round.
A red, green, or bluish spiny capsule, 1–2 cm (0.4–0.8 in) in diameter, with white to tan. Very poisonous seeds.
FLEPPC Category II – Invasive exotics that have increased in abundance or frequency but have not yet altered Florida plant communities to the extent shown by Category I species.
NW, NE, C, SW, SE
*Also known as: Ruellia coerulea
Ricinus communis, Castor Bean by Melissa H. Friedman, Michael G. Andreu, Heather V. Quintana, and Mary McKenzie FOR 244/FR 306 (2010)
1. Identification and Biology of Nonnative Plants in Florida’s Natural Areas – Second Edition, by K.A. Langeland, H.M. Cherry, et al. University of Florida-IFAS Publication # SP 257. 2008.
2. Invasive and Non-native Plants You Should Know - Recognition Cards, by A. Richard and V. Ramey. University of Florida-IFAS Publication # SP 431. 2007.
3. Integrated Management of Nonnative Plants in Natural Areas of Florida, by K. A. Langeland, J. A. Ferrell, B. Sellers, G. E. MacDonald, and R. K. Stocker. University of Florida-IFAS Publication # SP 242. 2011.