Melocactus matanzanus
Family: Cactaceae​
​Common Name: dwarf Turk's cap
​Origin: Melocactus matanzanus is endemic to the Matanzas and Las Villas provinces of Northern Cuba, among coastal shrublands in serpentine outcrops. Its habitat has been highly degraded by forestation, and now the species is critically endangered.
Description: M. matanzanus is a small, usually solitary cactus that develops a globular form, including 8 to 9 rounded ribs that are covered with whitish-gray or brown spines. Mature plants grow a stoutly cylindrical cephalium, bright-orange with white wool. During mid-summer, once specimens have reached 4-5 years, a ring of rose to carmine flowers will form upon the cephalium, blooming for a few hours around noon. Pink to red fruits will follow, tube-like with a waxy exterior.
  • Interesting Features:
    • M. matanzanus is one of the smallest species of cacti that develops a cephalium.
    • Unlike most plant species, the growth of Melocactus matanzanus is determinate, as the appearance of the cephalium will limit further extension. This, and the appearance of the cephalium, lead to the common name “dwarf Turk’s cap”.
  • Uses: Outside of cultivation, there are no ethnobotanical uses specifically recorded for M. matanzanus.
    • However, other Melocactus species have been utilized extensively - with the fruits consumed, kernel used to prepare medicinal syrup as a treatment for whooping cough, flesh burnt or cut as fodder, and the entire plant used in religious ceremonies.

Cultivation and Care:
  • Watering: Moderate
    • Irrigate thoroughly whenever soil is dry - even in winter - but do not allow to stand in water.
    • Watering should be done very carefully, as the dwarf Turk’s cap cannot survive dryness, but will easily rot under excessive moisture.
  • ​Soil: Grow with a porous, well-draining cactus soil that is sandy or gritty.
    • Additionally, a slightly acidic pH between 5.0 and 7.0 should be maintained for the best growth.
  • Lighting: Melocactus matanzanus requires as much sun as possible to encourage flowering and heavy spine formation, and growth will suffer in sites without bright light.
  • Propagation: Dwarf Turk’s cap propagates exclusively through seed, which should be sown from February to March in a covered container.
    • For the best results, maintain a germination temperature between 64.4 and 71.6°F.
  • Cold Tolerance: 30°F, USDA hardiness zones 10a to 11.
  • Special Accommodations: M. matanzanus is a difficult cactus to grow, as it requires careful watering, bright sun, and protection from frost.
    • Although tolerant to 30°F for brief periods of time, an ideal temperature should never fall below 46.4°F, or cacti will suffer.
    • ​Lastly, this species prefers restricted growth; plant in a container that is slightly too small, and repot sparingly – about once every 3 years, at the beginning of the growing season.

Sources:
  1. Llifle Encyclopedia of Cacti
  2. World of Succulents
  3. Dave’s Garden
  4. Plant Lust
  5. Plant Care Today
  6. Garden Tags
  7. Indoor Plant Care
  8. Journal of Ethnobiology and Ethnomedicine
See this species in the Mark Dimmitt Desert Plant Conservatory Virtual tour