Common Names: cow’s horn, cow’s horn succulent, cow’s horn Euphorbia
Geographic Origin: Euphorbia grandicornis is native to hot, dry, low altitude alluvial soils, usually with well-protected grass. The species occurs in small colonies within KwaZulu-Natal, Swaziland, Mozambique, and Kenya.
Description: The cow’s horn Euphorbia is a multistemmed succulent shrub that forms large bushy growths up to 6 feet tall and wide, often collapsing under its own weight. The green stems are uniquely twisted into triangular segments, covered with jointed, conspicuous spines that resemble a cow’s horns. Although tiny leaves will form between the spines in late summer, they are short-lasting and will dissipate.
Bright yellow cyathia appear in late spring, forming in groups of 3 above the terminal spines on the central segments. The middle flower will be stalkless and male, while the two outermost cyathia will be stalked, bisexual inflorescences. Shortly after flowering, the 3-lobed fruits will appear in rows on the angled ridge of branches, and will ripen to an attractive purple.
Cultivation and Care:
- Watering: Moderate
- Lighting: Provide full sun for long periods to encourage flowering and proper growth.
- Propagation: The cow’s horn succulent can be propagated through semi-hardwood cuttings or seed, although seeds are usually difficult to germinate or even locate. Allow cuttings to fully callous over before planting.
- Cold tolerance: 25°F, USDA hardiness zones 9b-11
- Special Accommodations: E. grandicornis is not very frost-hardy, and should be protected from freezing. Additionally, always wear gloves when handling, and goggles when grafting or cutting to avoid irritation from the toxic latex.