Subterranean Treasure: Euphorbia decaryi var. cap-saintemariensis

A critically endangered botanical jewel featuring crinkled, geometric foliage and a striking, caudex-forming silhouette.

1. Origin & History of Name: The genus name Euphorbia honors Euphorbus, the Greek physician to King Juba II of Numidia, who famously used the plant’s caustic latex for medicinal purposes. The species name decaryi commemorates Raymond Decary, a prolific French botanist who collected extensively in Madagascar during the 1920s. The varietal name refers specifically to Cap Sainte Marie, the southernmost point of Madagascar, where this distinct population was identified.
2. Morphology: This variety is characterized by its rhizomatous growth habit and a thickened, succulent rootstock known as a caudex. The epidermis of the leaves is a deep bronze to olive green, featuring highly undulated or "crinkled" margins that reduce water loss. Unlike many columnar Euphorbias, it lacks prominent costae (ribs), instead forming a prostrate mat of spiraling, scale-like leaf bases and small, bell-shaped cyathia (false flowers).
3. Habitat & Origin: This is a wild species endemic to a very narrow strip of coastal limestone and sand dunes in the Cap Sainte Marie Special Reserve, Madagascar. Due to its extremely limited range, it is listed on CITES Appendix I. Our specimens are exclusively nursery-grown from cultivated mother stock to ensure botanical sustainability and the protection of wild populations.
4. Cultivation Profile:
   • Substrate: Requires an open-structured, mineral-based mix. Use a blend of coarse river sand, crushed grit, and a small fraction of coco-peat (80:20 ratio) to ensure rapid drainage.
   • Light: Thrives in bright, indirect light. In the Indian subcontinent, it should be protected from the harsh midday sun to prevent leaf scorch, though high light levels are necessary to maintain its deep bronze pigmentation.
   • Water/Dormancy: Provide regular watering during the humid summer and monsoon, allowing the substrate to dry completely between cycles. During the cooler months (late November to February), the plant undergoes semi-dormancy; reduce water significantly to prevent root rot in the cooler, stagnant air.
5. Scientific/Historical Anecdote: The Euphorbia genus is one of the most diverse in the plant kingdom, containing over 2,000 species. A fascinating evolutionary trait of E. decaryi var. cap-saintemariensis is its "geophytic" tendency; in the wild, the plant often grows almost entirely buried in sand, leaving only the tips of its crinkled leaves exposed to survive the abrasive, salt-laden winds of the Malagasy coast.