Accession Count: 1
Common Name:
crown of thorns
Family Name:
Euphorbiaceae
Botanical Name:
Euphorbia milii
Sub Species:
Variety:
Forma:
Cultivar:
Characteristics:
The crown of thorns is a perennial and deciduous shrub that can also be described as succulent because of its thick stems that help retain moisture (1). It can grow up 1-2 m (3- 6 ft) tall. Its stems are long, brownish-grey in color and covered in 2.5 cm long grey spines (1). Leaves are clustered at the apex of the stems, are alternately arranged with a very short petiole, simple, 1.5- 5 cm (about 0.38- 1.97 in) long and 0.8- 1.8 cm (about 0.71 in) wide and obovate (2). Flowers are also borne on the apex of stems with a large extended pedicel that comprise the cyathium inflorescences which is common among other members of the genus Euphorbia (3). Cyathium are inflorescences that include a cup-like base, formed from the fused bracts, which subtend the female reproductive structures and the male flowers. The male and female flowers are separated by a pedicel and collectively form the inflorescence (3). A noticeable feature of its flowers is its two bright red bracts that surround the small yellow male or female flower in the center. Its 3.5 cm (1.5 in) long bracts serve as an advantage to attract pollinators (1, 2). Fruits are brown, are capsules less than a centimeter long, and contain 1 seed per capsule (2).
Compound:
Eup mil
Geographic Origin:
Middle East
Ecozone Origin:
Palearctic
Biome Origin:
Natural History:
This plant is native to Madagascar where it grows at elevations from sea level to 1500 m (about 4921 ft) (4). In cultivation, it is widely distributed in countries throughout Asia, South America, North, America, and Europe, occasionally appearing in those countries at slightly higher elevations (4, 5). The crown of thorns is significant in its native ecological habitat because it provides food and shelter to a wide range of wildlife (1).
The genus of this species, Euphorbia, contains over 2,000 species and is believed to be derived from a Greek physician’s name, Euphorbus, who treated king of Mauretania with medicinal plants (1, 2). Its specific epithet is named after France Governor Baron Milius, who is believed to have introduced this plant in France during 1821 (2). Its common names, crown of thorns or christplant, refers to the belief that the stems of this plant were worn by Jesus Christ during his crucifixion (2).
Cultivation Notes:
This plant is cold hardy to USDA zones 10-12, so it isn't completely hardy to Arizona’s low deserts (8). Although some reports have specified that this plant is potentially cold hardy to USDA zones 9-11 (9), this plant usually benefits from efforts to reduce freezing and cold injury when grown outside its primary USDA hardiness zones. Minimal watering during winter months reduces risk of freezing and sensitivity to cool moist soil conditions during the winter months (8). This plant tolerates poor soils but prefers sandy and loamy soils that ensure adequate drainage (1). The crown of thorns does well in full sun, but in warmer climates, it could be more beneficial to be planted in partial shade away from afternoon sun (9). Moderate watering is preferred by this plant but would perform better with supplemental watering during hot seasons for better blooms and foliage (8). It can be propagated by stem cuttings, tip cuttings, or by seed (1, 9).
Ethnobotany:
The crown of thorns is frequently cultivated for ornamental usage and is commonly grown as low hedges in landscapes (4). This plant has also been used in traditional folk remedies to treat skin infections, cancer, and liver ailments (6). In China, it is also cultivated for its medicinal properties in its sap, roots, leaves, flowers, and stems (7). Its sap, roots, leaves and stems can be used to remove harmful toxins, loosen phlegm, and reduce pus. Its flowers cool blood and stop bleeding (7).
Height:
0 - 5 feet
Width:
0 - 5 feet
Growth Rate:
Slow Growing
Grow Season:
Winter
Flower Season:
Spring
Color:
Red
Function:
Accent
Spread:
Non-spreading
Allergen:
Allergenic
Invasive:
Toxicity:
Toxic
Hardy:
Semi-hardy
Water Use:
Low water Use
