Scientific Name
Discocactus horstii Buining & Brederoo
Synonym(s)
Discocactus woutersianus
Scientific Classification
Family: Cactaceae
Subfamily: Cactoideae
Tribe: Trichocereeae
Genus: Discocactus
Etymology
The specific epithet "horstii" (pronounced "im-mak-yoo-LAH-tuh") honors Leopoldo Horst (1918-1987), a German-born Brazilian cactus collector and exporter in Rio Grande do Sul. He discovered this species on the Serra do Barão, Minas Gerais, Brazil, in 1971.
Origin
Discocactus horstii is native to Minas Gerais, Brazil, at an altitude of about 3280 feet (1000 m).
Description
Discocactus horstii is a small cactus with a spherical, usually solitary stem, which has 12 to 22 prominent ribs and is topped with a flat cephalium. This cactus can grow up to 2 inches (5 cm) tall, while the cephalium can reach a diameter of 2.4 inches (6 cm). The stem is initially green and turns dark red or brown as the plant matures.
The flowers of Discocactus horstii are nocturnal, white, and fragrant, blooming in the summer. They can measure up to 3 inches (7.5 cm) in length and 2.4 inches (6 cm) in diameter. The fruits are white and contain black seeds.
Hardiness
USDA hardiness zone 10a to 11b: from 30°F (-1.1°C) to 50°F (10°C).
How to Grow and Care
Discocactus is probably one of the most challenging cacti to grow on its own roots and is almost always seen as a grafted plant. If growing on its own roots is attempted, the soil must be extremely free-draining, and watering should only take place after the compost has dried out and then only on sunny and warm days.
The species of Discocactus are tropical plants and should be kept warm in winter. The grafted plants are less cold-sensitive, but none have any frost tolerance. Mature Discocactus stop growing and instead divert their energy into developing a cephalium. The cephalium is a specialized flowering head, generally covered with fibers.
Discocactus will take full sun but prefers a little shade in the afternoon after the compost has dried out—water with extreme care.
See more at How to Grow and Care for Discocactus.
Links
- Back to genus Discocactus
- Succupedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus
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