Euphorbia flanaganii aka Medusa's Head

Euphorbia flanaganii is a dwarf succulent that stays relatively compact. The central caudex grows 3-5 cm tall, while the snake-like branches spread horizontally to create a medusa-like rosette up to 40 cm (16 inches) in diameter. It is a fast-growing species that readily produces offsets, eventually forming impressive specimen plants with numerous radiating arms.

Euphorbia flanaganii thrives in warm temperatures, preferring 65-70°F (18-21°C) and above. It can tolerate summer temperatures exceeding 100°F (38°C) in its native habitat. However, it cannot handle frost or freezing temperatures—do not let temperatures drop below 30°F (-1°C). In its natural South African habitat, it experiences frost-free conditions with summer averages around 32°C.

Yes, Euphorbia flanaganii produces clusters of small yellow cyathia (the characteristic Euphorbia flower structure) from late summer through autumn. The flowers appear at the tips of the central branches and are around 4mm in size with yellow-green bracts. While not particularly showy, the flowers are fragrant and attract butterflies, bees, and other pollinating insects. After pollination, capsular fruits develop and split open to release seeds.

Beyond the standard form, there are two popular cristata (crested) varieties. The branch cristation form, often called 'Green Coral', develops wavy, fan-shaped crested branches that resemble coral—it can grow 12-15 cm high and 30 cm wide. The caudex cristation has a crested base with normal cylindrical branches above. These mutations occur naturally but are propagated through cuttings as they don't typically flower.

Euphorbia flanaganii can grow outdoors year-round in USDA zones 9-11 where temperatures stay above 30°F (-1°C). It thrives in warm, frost-free climates and grows naturally along the South African coast from the Eastern Cape to KwaZulu-Natal. In colder regions, grow it outdoors during summer but bring it inside before frost. It tolerates full sun but appreciates afternoon shade in very hot climates to prevent heat stress.

Euphorbia flanaganii generally requires minimal pruning. You may remove dead or damaged branches for aesthetics, but always wear gloves as the milky latex sap is caustic and can cause skin irritation. If a branch becomes too long or unbalanced, it can be trimmed back—the cut ends will callous over. Removed healthy branches can be used for propagation after allowing the cut to dry for a day.

Euphorbia flanaganii prefers to be slightly root-bound, so repotting is only needed every 2-3 years or when roots fill the pot and growth slows. Spring is the best time to repot. Choose a pot with drainage holes only slightly larger than the current one, and use well-draining succulent mix with added pumice or perlite. Handle carefully to avoid the toxic sap, and water sparingly after repotting to prevent root rot.

Euphorbia flanaganii is easy to propagate. The most common method is through offsets—mature plants produce baby plants (pups) at the branch tips that can be cut off, dried for a day, and planted in well-draining soil. Seeds can also be sown in autumn using coarse river sand as a medium. Apply fungicide to cut surfaces to prevent rot. Division of the caudex is possible in spring (August-October in the Southern Hemisphere). Always wear gloves when handling to avoid the toxic latex.

Yellowing in Euphorbia flanaganii can have several causes. Overwatering is most common—ensure soil dries between waterings and check for root rot. Underwatering can also cause yellowing, as the plant curls its arms inward when thirsty. Sudden exposure to intense sunlight without acclimation can cause sun stress. Heavy, poorly-draining soil retains too much moisture. Winter dormancy may also cause some natural yellowing of older branches.

Euphorbia flanaganii is primarily susceptible to mealybugs and spider mites. Mealybugs often target the roots, though they can appear on branches too—check for white cottony masses. Spider mites cause stippling on the stems. Treat infestations by wiping with cotton wool dipped in rubbing alcohol. Root rot from overwatering is the main disease concern; prevent it with well-draining soil and allowing the medium to dry between waterings.

Euphorbia flanaganii is pollinated by insects, primarily butterflies, bees, and other flying pollinators attracted to the small yellow cyathia flowers. The flowers bloom from late summer through autumn and produce a subtle fragrance. After successful pollination, capsular fruits develop that eventually dry and split open to release seeds. Seeds are then dispersed and banked in the soil during winter, germinating when conditions are favorable.

If your Euphorbia flanaganii branches are curling inward toward the center or looking limp, it's typically a sign of dehydration—unlike most succulents, this species doesn't tolerate prolonged drought. Water thoroughly when you notice this response. However, if the branches feel soft or mushy rather than just curled, overwatering and potential root rot may be the cause. Check the roots and repot in fresh, dry soil if rot is present.

The flowers of Euphorbia flanaganii are described as fragrant according to botanical sources. The small yellow cyathia that appear in late summer through autumn produce a subtle scent that helps attract pollinating insects like butterflies and bees. The plant itself (stems and leaves) does not have a notable fragrance.

In South African traditional medicine, Euphorbia flanaganii has documented medicinal uses. The latex is used during pregnancy, as a purgative, and applied to wounds and skin lesions. The whole plant is collected and sold in traditional 'muthi' markets. However, due to the plant's toxicity, these uses should only be undertaken by knowledgeable practitioners. This harvesting pressure, combined with habitat loss, has contributed to the species being listed as Vulnerable.