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Ricinus communis is often confused with:
Kalopanax septemlobus Kalopanax septemlobus
Native alternative(s) for Ricinus communis:
Aronia melanocarpa Form
Callicarpa americana Callicarpa americana in summer in Moore County
Ilex vomitoria Ilex vomitoria
Rhus aromatica Rhus aromatica
Plants that fill a similar niche:
Lantana camara Lantana camara flower
Dianthus chinensis Dianthus chinensis
Clematis terniflora form in landscape on arbor in late summer
Ricinus communis has some common insect problems:
Twospotted Spider Mites on Landscape Plants

Castor Oil Plant Ricinus communis

Phonetic Spelling
RISS-ih-nuss kom-YOO-niss
This plant has high severity poison characteristics.
See below
Description

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 a 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.

 

 

 

 

Profile Video:
See this plant in the following landscape:
Cultivars / Varieties:
  • 'Carmencita Bright Red'
    Dark bronze-red leaves, bright red flowers, and scarlet seed pods
  • 'Carmencita Pink'
    Pinkish-red stems and seed pods
  • 'Carmencita Rose'
    Bluish-green leaves and peach colored seed pods
  • 'Gibsonii'
    Dark red tinged leaves and pink seed pods, grows 4 to 5 feet tall
  • 'Red Spire'
    Red stems, bronze leaves, red seed pods
  • 'Ricinus'
  • 'Sanguineus'
    Blood red stems and leaves
'Carmencita Bright Red', 'Carmencita Pink', 'Carmencita Rose', 'Gibsonii', 'Red Spire', 'Ricinus', 'Sanguineus'
Tags:
#small tree#poisonous#full sun tolerant#drought tolerant#shrub#purple leaves#weedy#fall interest#large shrub#summer flowers#deer resistant#herbaceous perennials#problem for cats#problem for dogs#skin irritation#problem for children#problem for horses#annual#full sun#foliage#landscape plant sleuths course
 
Cultivars / Varieties:
  • 'Carmencita Bright Red'
    Dark bronze-red leaves, bright red flowers, and scarlet seed pods
  • 'Carmencita Pink'
    Pinkish-red stems and seed pods
  • 'Carmencita Rose'
    Bluish-green leaves and peach colored seed pods
  • 'Gibsonii'
    Dark red tinged leaves and pink seed pods, grows 4 to 5 feet tall
  • 'Red Spire'
    Red stems, bronze leaves, red seed pods
  • 'Ricinus'
  • 'Sanguineus'
    Blood red stems and leaves
'Carmencita Bright Red', 'Carmencita Pink', 'Carmencita Rose', 'Gibsonii', 'Red Spire', 'Ricinus', 'Sanguineus'
Tags:
#small tree#poisonous#full sun tolerant#drought tolerant#shrub#purple leaves#weedy#fall interest#large shrub#summer flowers#deer resistant#herbaceous perennials#problem for cats#problem for dogs#skin irritation#problem for children#problem for horses#annual#full sun#foliage#landscape plant sleuths course
  • Attributes:
    Genus:
    Ricinus
    Species:
    communis
    Family:
    Euphorbiaceae
    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.
    Life Cycle:
    Annual
    Perennial
    Woody
    Recommended Propagation Strategy:
    Seed
    Country Or Region Of 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
    Dimensions:
    Height: 6 ft. 0 in. - 10 ft. 0 in.
    Width: 2 ft. 0 in. - 4 ft. 0 in.
  • Whole Plant Traits:
    Plant Type:
    Annual
    Herbaceous Perennial
    Poisonous
    Shrub
    Tree
    Woody Plant Leaf Characteristics:
    Broadleaf Evergreen
    Habit/Form:
    Dense
    Erect
    Multi-stemmed
    Growth Rate:
    Rapid
    Maintenance:
    Low
  • Cultural Conditions:
    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 To Plant:
    3 feet-6 feet
    6-feet-12 feet
    USDA Plant Hardiness Zone:
    9b, 9a, 10b, 10a, 11b, 11a
  • Fruit:
    Fruit Color:
    Brown/Copper
    Green
    Purple/Lavender
    Red/Burgundy
    Fruit Value To Gardener:
    Showy
    Fruit Type:
    Capsule
    Fruit Length:
    < 1 inch
    Fruit Width:
    < 1 inch
    Fruit Description:
    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.
  • Flowers:
    Flower Color:
    Gold/Yellow
    Green
    Flower Inflorescence:
    Panicle
    Spike
    Flower Value To Gardener:
    Showy
    Flower Bloom Time:
    Fall
    Summer
    Flower Shape:
    Cup
    Flower Description:
    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.
  • Leaves:
    Woody Plant Leaf Characteristics:
    Broadleaf Evergreen
    Leaf Color:
    Green
    Purple/Lavender
    Leaf Feel:
    Glossy
    Leaf Type:
    Compound (Pinnately , Bipinnately, Palmately)
    Simple
    Leaf Arrangement:
    Alternate
    Leaf Shape:
    Palmatifid
    Peltate
    Leaf Margin:
    Serrate
    Hairs Present:
    No
    Leaf Width:
    > 6 inches
    Leaf Description:
    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.
  • Bark:
    Bark Description:
    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:
    Stem Color:
    Green
    Purple/Lavender
    Red/Burgundy
    Stem Is Aromatic:
    No
    Stem Description:
    The stems are red to green or purple, erect, and branched.
  • Landscape:
    Landscape Location:
    Container
    Design Feature:
    Specimen
    Resistance To Challenges:
    Deer
    Drought
    Problems:
    Poisonous to Humans
    Problem for Cats
    Problem for Children
    Problem for Dogs
    Problem for Horses
    Weedy
  • Poisonous to Humans:
    Poison Severity:
    High
    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.
    Poison Toxic Principle:
    Ricin, a phytotoxalbumin, plus ricinine, an alkaloid
    Causes Contact Dermatitis:
    Yes
    Poison Part:
    Flowers
    Leaves
    Sap/Juice
    Seeds