Scientific Name
Gymnocalycium mihanovichii 'Hibotan'
Common Name(s)
Ruby Ball, Red Cap Cactus, Red Hibotan, Hibotan, Moon Cactus 'Hibotan'
Synonym(s)
Gymnocalycium mihanovichii var. friedrichii f. rubra, Gymnocalycium mihanovichii var. rubrum, Gymnocalycium mihanovichii f. rubra, Gymnocalycium friedrichii 'Rubra'
Scientific Classification
Family: Cactaceae
Subfamily: Cactoideae
Tribe: Trichocereeae
Genus: Gymnocalycium
Description
Gymnocalycium mihanovichii 'Hibotan' is a popular cactus with usually red-colored stems, but also orange, dark purplish, yellow, or even white, because they contain little chlorophyll or even no chlorophyll. At least 16 color variants have been described. Since chlorophyll is necessary for photosynthesis, these mutations die as seedlings unless grafted onto another cactus with normal chlorophyll. The stems are flattened globose to elongated globose, up to 4 inches (10 cm) tall and up to 5 inches (12.5 cm) in diameter, often branching profusely from the sides. They have 8 to 14 ribs, very prominent, and sharp banded whit strong dark brown markings, especially when young. Spines are light to dark brown, somewhat twisted, and up to 0.4 inches (1 cm) long. Flowers are pale-pink to purplish-pink and up to 3 inches (7.5 cm) long. Fruits are gray-green to pinkish-red, up to 1.6 inches (4 cm) long, and up to 0.4 inches (1 cm) in diameter.

Hardiness
USDA hardiness zones 9b to 11b: from 25 °F (−3.9 °C) to 50 °F (+10 °C).
How to Grow and Care
Some Gymnocalyciums are shade-seeking in the wild, among shrubs or grasses, while others grow completely exposed. Therefore, some will need light shading from the sun in the hottest months, but to overdo this will result in the loss of flowers.
The balance of the potting medium should be sufficient to allow good drainage so that the plants do not sit in soggy soil for more than a day or two after watering.
While the plants are growing well in the summer months, watering can be frequent (weekly for small plants in small pots) but always allowing the compost nearly to dry out before rewatering. Watering in the winter months at all is unwise and certainly not necessary. The difficult times are spring and autumn.
Those species which produce offsets can be readily propagated by cuttings. Gymnocalycium seed germinates well when fresh and will keep for a few years if stored in cold conditions.
See more at How to Grow and Care for Gymnocalycium
Origin
This cactus comprises a large group of popular cultivars characterized by more or less red-colored stems.
Graft-chimaeras
Links
- Back to genus Gymnocalycium
- Succulentopedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus
Photo Gallery
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