Euphorbia tuberculata is a medusoid species previously synonymized with Euphorbia caput-medusae. At first glance, they look very similar, but there are some distinguishing features. The peduncles of Euphorbia tuberculata are up to 2 inches (5 cm) long, while those of Euphorbia caput-medusae are only up to 0.4 inches (1 cm) long. Moreover, Euphorbia tuberculata has a less developed main stem and 4 bracts under the involucre, whereas Euphorbia caput-medusae has 5 to 7.
Scientific Name
Euphorbia tuberculata Jacq.
Synonym(s)
Dactylanthes tuberculata, Medusea tuberculata, Treisia tuberculata
Scientific Classification
Family: Euphorbiaceae
Subfamily: Euphorbioideae
Tribe: Euphorbieae
Subtribe: Euphorbiinae
Genus: Euphorbia
Etymology
The specific epithet "tuberculata (tew-ber-kew-LAY-tuh)" means "warty, tuberculate" and refers to the tuberculate branches of this species.
Origin
Euphorbia tuberculata is native to South Africa. It grows in sand flats in dry, open areas from Malmesbury in the Western Cape to Little Namaqualand in the Northern Cape province.
Description
Euphorbia tuberculata is a succulent plant with a stout, inverted cone-shaped main stem that produces many erect or decumbent branches from the top. The main stem is either wholly or partly buried in the soil. The branches are tuberculate, thickened at the upper part, and can reach up to 1.6 inches (4 cm) in diameter. They are spineless but have persistent remains of the peduncles. The branches are dull green and may sometimes turn whitish with age. The tubercles are rhomboid, more prominent in the younger specimens, and arranged in spirals along the branch.
This plant usually blooms in winter and spring. The cyathia are solitary and produced several together near the tip of the branches on peduncles that arise from the axils of the tubercles. They can reach up to 0.7 inches (1.8 cm) in diameter and consist of bowl-shaped involucre with five glands that are palmately divided halfway down into 3 to 6 creamy processes. The undivided part of the glands is green, while the processes are creamy but become crimson with age. The peduncles can grow up to 2 inches (5 cm) long, becoming woody soon after shedding the fruit. The fruits are 3-lobed capsules with a distinct keel-like ridge on the back of each lobe. They can be smooth or have longish white hairs and reach up to 0.25 inches (0.6 cm) in length and diameter.
How to Grow and Care for Euphorbia tuberculata
Light: Providing your Euphorbia tuberculata with plenty of sunlight is important for optimal growth. Place it near a sunny window or move it to your balcony or garden during the warmer months, gradually increasing sun exposure to avoid sunburn.
Soil: Use a well-draining soil, either a commercial potting mix formulated for succulents or create your own well-draining soil.
Temperature: While high summer temperatures are not a problem, low winter temperatures can damage or kill your plant. Euphorbia tuberculata grows best in USDA Plant Hardiness Zones 10a to 11b, with average minimum winter temperatures ranging from 30 to 50 °F (-1.1 to 10 °C).
Watering: From spring to fall, water the plant when the soil's top inch (2.5 cm) feels dry. Reduce watering in winter and give it just enough water to prevent wilting. In the warm season, evening is the best time of the day for watering.
Fertilizing: To ensure the potted plant receives sufficient nutrients, apply a balanced fertilizer in a 10-10-10 NPK formulation, diluted to 1/4 strength weekly during the growing season.
Repotting: Although your Euphorbia tuberculata does not need to be repotted often, it will benefit from repotting when it outgrows its pot. The repotting is best done in early spring at the beginning of the growing season. Wear gloves, protective clothing, and appropriate eye protection when handling this plant.
Propagation: The easiest and quickest way to propagate this plant is by stem cuttings. Although it can be started from seeds, it can be difficult for them to germinate. Be sure to take cuttings only during the growing season; spring is the ideal time to sow seeds.
Learn more at How to Grow and Care for Euphorbia.
Toxicity of Euphorbia tuberculata
Euphorbia tuberculata produces a poisonous white milky sap that may cause burns or irritation if it comes into contact with the skin or eyes. Therefore, it is best to keep this plant away from children and pets.
Links
- Back to genus Euphorbia
- Succupedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus
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