Melocactus matanzanus

Wild home of Melocactus matanzanus

Melocactus matanzanus is restricted to the Matanzas region of Cuba, where it belongs to seasonally dry tropical vegetation. Its very small natural range makes the species especially vulnerable to habitat damage and collecting, and it is assessed as Endangered.

At maturity, the cactus forms a woolly cap called a cephalium and ordinary body growth stops. The cephalium repeatedly produces flowers, fruit and seed. Seeds can remain inside it and continue to be released even after the parent plant dies, an unusual form of delayed dispersal.

International trade in M. matanzanus is regulated through CITES Appendix II. Plants raised in cultivation provide an alternative to removing specimens from its restricted Cuban population.

Growing succulents in containers

• Warm arrival: Keep the cactus warm and dry around the body after delivery. Avoid immediate repotting, especially after it has formed the woolly flowering cap known as a cephalium, because mature plants have sensitive roots.
• Light: Very bright conditions are essential, with direct sun filtered or introduced gradually. Sudden exposure can scar the green body and the area beside the cephalium.
• Water: During warm active growth, wet the mineral mix fully and let it dry substantially before watering again. Use much less in winter, but do not combine prolonged total drought with cold conditions.
• Substrate: Use a porous mineral cactus medium with excellent drainage.
• Temperature: This tropical cactus is more cold-sensitive than many desert species.
• Repotting: Repot only when necessary, preserving the fine roots and choosing a container only modestly larger. Do not pick apart or repeatedly wet the woolly cephalium.
• Feeding and propagation: Apply low-nitrogen cactus fertiliser during warm growth. Propagation is by seed, since the species does not normally produce offsets.

Responding when problems appear

• Woolly flowering cap: The cephalium is normal adult reproductive growth, not rot, a graft or a pest nest. Do not pull it apart or wet it repeatedly.
• Soft dark lower body: Combined with wet mix or foul roots, this is consistent with active rot. Stop watering, keep the cactus warm and inspect the roots without causing further damage.
• Dry corking at the base: Firm dry cork can develop with age. Tissue that is spreading, wet, soft or odorous is abnormal and should be treated as possible rot.
• Pale then corky patches: This is sunburn from abrupt exposure. Filter the strongest sun and acclimatise gradually; the scar will remain permanent.
• Rusty fine stippling: Spider mites can mark the tender skin. Inspect for moving mites or webbing so natural bristles and cephalium colour are not mistaken for infestation.
• Failure to take up water: Root mealybugs or roots lost after repotting may be hidden while the cactus body still looks full. Keep conditions stable and avoid repeated watering until the roots are assessed.
• Delayed decline after repotting: Mature roots are highly sensitive. Do not repot again in response; protect the plant from cold and excess moisture while it attempts to re-establish.

Melocactus matanzanus has sharp parts

• Keep this plant away from children and pets because its effects after chewing or swallowing are unclear.
• Sharp spines can puncture the mouth, eyes, skin or paws.
• Handle it carefully. Contact a veterinarian or medical professional after a serious injury, especially to the eye.

Why is it called Melocactus matanzanus?

Melocactus combines melo, melon, with cactus, describing the rounded body. Matanzanus means from Matanzas and links the species with Matanzas, Cuba.

Johann Heinrich Friedrich Link and Christoph Friedrich Otto established the genus Melocactus in 1827 in Verhandlungen des Vereins zur Beförderung des Gartenbaues in den Königlich Preussischen Staaten, volume 3, page 417.

Hermano León first described Melocactus matanzanus in 1934 in Memorias de la Sociedad Cubana de Historia Natural “Felipe Poey”, volume 8, page 206.