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African Wonder Tree

Ricinus communis (RISS-ih-nuss kom-YOO-niss)

Family: Euphorbiaceae Non-native Shrub (3-15 ft)

Castor Bean is an exotic ornamental, semi-woody, fast-growing, large shrub or small tree that is extremely toxic to humans. It can be fatal if only a few seeds are ingested and also causes contact dermatitis when the foliage is handled. It is an herbaceous perennial in winter hardy zones 9 to 11. In colder climates, it is a warm weather annual that readily reseeds itself. The Castor Bean has large, palmately lobed leaves, spiking yellowish-greenish flowers, and spiny seed capsules. It is a member of the Euphorbiaceae or spurge family. This plant is native to tropical east Africa, but it has naturalized and weedy in many tropical and subtropical areas around the world including the United States. It is usually found along riverbeds, railroads, roadsides, fields, pastures, or other disturbed areas. Castor bean is a noxious weed in southern and central California. The plant is classified as Category II invasive species in the State of Florida. The genus name, Ricinus , is the Latin word for "tick." This name was given since the seeds resemble a species of European tick. The epithet, communis , means common. Plant in full sun in rich moist soils. Fertilize regularly for the best growth. Pruning may be necessary to shape the plant. Plants will have low drought tolerance until well established. This shrub is not wind resistant and is easily blown over. Staking may be required. It produces a large number of seeds and readily reseeds itself. Every part of the plant is poisonous if ingested. The castor bean contains a highly poisonous substance known as ricin that when inhaled or ingested can be lethal to humans and animals. As a preventative measure, the seed capsules may be pinched off when they are small to remove the poisonous seeds from the plant. Handling the foliage may cause severe contact dermatitis Wear gloves and other protective equipment to avoid allergic skin reactions. Do not plant this in areas where children or pets play due to its toxicity. In the appropriate area, the beautiful and bold foliage adds color and texture to the landscape. Consider this plant as a specimen, container plant, or informal hedge. It is important to remember that this plant grows very fast, and seeds germinate regularly. Plant with purpose and maintain the area to prevent invasiveness. Perhaps better yet, consider a native alternative such as the American Beautyberry, Yaupon Holly, or Fragrant Sumac. Seasons of Interest: Bloom: Summer and Fall Foliage: Spring, Summer, and Fall Fruits : Fall Quick ID Hints: annual or herbaceous perennial shrub or small tree, usually up to 6 to 10 feet tall and 2 to 4 feet wide stems are red to green or purple leaves are glossy, green, star-shaped with 5 to 11 points, serrated margins, and measure 6 to 30 inches wide non-petaled yellowish-green flowers appear on spikes measuring up to 18 inches long on the top of the stem fruit capsule is red, green, or purple, round, covered in dense spines seeds are mottled, smooth, and resemble an engorged dog tick Insects, Diseases, and Other Plant Problems: The castor bean has no serious insects or disease problems. Spider mites occasionally attack drought-stressed plants. VIDEO created by Andy Pulte for “Landscape Plant Identification, Taxonomy, and Morphology” a plant identification course offered by the Department of Plant Sciences, University of Tennessee.

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 65 attributes.

How it fits the guild

Guild layer 3 - Shrub (3-15 ft) Optimal soil pH Acid (<6.0); Alkaline (>8.0); Neutral (6.0-8.0)
See companions & conflicts ↓

Companions & Conflicts

Curated pairwise relationships between this plant and others in the library — who feeds whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.

No curated interactions recorded for this species yet.

Also noted by NC State

Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.

Often confused with Kalopanax septemlobus
Fills a similar niche Dianthus chinensis Lantana camara Lantana camara 'Miss Huff'

Full plant profile

Growing Conditions
Plant type
Annual; Herbaceous Perennial; Poisonous; Shrub; Tree
Life cycle
Annual; Perennial; Woody
USDA zones
9a, 9b, 10a, 10b, 11a, 11b
Light
Full sun (6 or more hours of direct sunlight a day)
Soil texture
Loam (Silt); Sand
Soil pH
Acid (<6.0); Alkaline (>8.0); Neutral (6.0-8.0)
Soil drainage
Good Drainage | Moist | Occasionally Dry
Available space
3 feet-6 feet; 6-feet-12 feet
Mature size
Height: 6 ft. 0 in. - 10 ft. 0 in. | Width: 2 ft. 0 in. - 4 ft. 0 in.
Growth rate
Rapid
Maintenance
Low
Canopy layer
3 - Shrub (3-15 ft)
Form & Appearance
Habit / form
Dense; Erect; Multi-stemmed
Foliage
Broadleaf Evergreen
Leaf color
Green; Purple/Lavender
Leaf type
Compound (Pinnately , Bipinnately, Palmately); Simple
Leaf arrangement
Alternate
Leaf shape
Palmatifid; Peltate
Leaf margin
Serrate
Leaf feel
Glossy
Leaf size
> 6 inches wide
Hairs present
No
Leaf detail
Leaves are large, alternate, simple, palmately lobed, and glossy green. They have 5 to 11 pointed lobes. The margins are toothed, and the leaf measures can be from 6 to 30 inches wide. They resemble a star.
Flower color
Gold/Yellow; Green
Flower value
Showy
Flower form
Panicle; Spike
Flower shape
Cup
Flower detail
The flowers are yellowish-green and without petals and appear in tall spikes up to 18 inches long. There are male and female flowers on the same spike. They are pediculate with a 5-parted calyx with many branching stems. The male flowers have cream or yellow stamens. Each female flower has a red stigma and is borne on the tips of the spikes. They bloom from August to November.
Bloom time
Fall; Summer
Fruit color
Brown/Copper; Green; Purple/Lavender; Red/Burgundy
Fruit type
Capsule
Fruit value
Showy
Fruit size
< 1 inch long, < 1 inch wide
Fruit detail
The fruits are small, round, red, green, or purple capsules that are covered with dense spines. The capsule turns brown as it matures. They measure 0.5 to 1-inch in diameter and contain three seeds. The seeds are smooth, shiny, and mottled black, gray, brown, yellow-brown, and maroon and white. The seeds resemble a dog tick.
Bark detail
The trunk is semi-woody in warm climates and can grow to 1 foot in diameter. In cooler climates, the plant remains herbaceous and is slower growing.
Stem color
Green; Purple/Lavender; Red/Burgundy
Stem detail
The stems are red to green or purple, erect, and branched.
Wildlife & Ecology
Native status
Non-native
Origin
Northeastern Africa to the Middle East
Distribution
Naturalized in tropical and subtropical areas around the world including Australia, Mexico, New Zealand, South America, and the United States. Introduced in AL, AZ, AR, CA, CT, DC, DE, FL, GA, HI, IL, KY, LA, MA, MI, MS, MO, NC, NH, NY, OH, PA, TN, TX, and VA.
Play value
Colorful; Textural
Food & Medicine
Fruit type
Capsule

Uses (ethnobotany)

Castor oil is a non-toxic vegetable oil that is extracted from the seeds of this plant. It is used in fabrics, paints, varnishes, ink, crayons, dyes, and ointments. Castor oil is used as a laxative. It has also been used topically to treat ringworm and warts.

Landscape Use
Landscape location
Container
Design feature
Specimen
Garden tags
#poisonous #fall interest #summer flowers #problem for cats #problem for children #problem for dogs #problem for horses #full sun tolerant #foliage #purple leaves #landscape plant sleuths course #herbaceous perennial #annual #skin irritation #drought tolerant #small tree #full sun #shrub #large shrub #deer resistant #poisonous seed #weedy
Problems & Resistance
Insect problems
Twospotted Spider Mites on Landscape Plants
Problems
Poisonous to Humans; Problem for Cats; Problem for Children; Problem for Dogs; Problem for Horses; Weedy
Resistant to
Deer; Drought
Propagation
Seed
Poison severity
High
Poison parts
Flowers; Leaves; Sap/Juice; Seeds
Poison symptoms
The seeds can the toxin ricin. If it is ingested or inhaled can be lethal to humans and animals. Immediate or delayed nausea, vomiting, abdominal pain, bloody diarrhea, weakness, colic, depression, loss of appetite, trembling, sweating, loss of coordination, difficulty breathing, sweating, progressive central nervous system depression and fever, convulsions, coma; may be fatal; severe allergic reaction in certain individuals following skin contact with broken seeds. May also be fatal to livestock and pets.
Toxic principle
Ricin, a phytotoxalbumin, plus ricinine, an alkaloid
Contact dermatitis
Yes
Toxicity summary
High severity poison; parts: Flowers; Leaves; Sap/Juice; Seeds; contact dermatitis

Planted at Hunnicutt

Nobody’s planted this one yet.