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.
Appearance
Many-branched; annual or perennial shrub, tree or herb, 1–5 m (3.3–16.5 ft) tall.
Leaves
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.
Flowers
Conspicuous, upright spikes; sepals 5, petals 0; male flowers yellow; female flowers pink to pinkish red; appearing nearly year-round.
Fruit
A red, green, or bluish spiny capsule, 1–2 cm (0.4–0.8 in) in diameter, with white to tan. Very poisonous seeds.
Ecological threat
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.
Distribution
NW, NE, C, SW, SE
Text from Invasive and Non-native Plants You Should Know - Recognition Cards 2
*Also known as: Ruellia coerulea
More Resources
View the herbarium specimen image from the University of Florida Herbarium Digital Imaging Projects.
Ricinus communis, Castor Bean by Melissa H. Friedman, Michael G. Andreu, Heather V. Quintana, and Mary McKenzie FOR 244/FR 306 (2010)
Citations
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.
