Scientific Name
Gymnocalycium ragonesei A.Cast.
Synonym(s)
Gymnocalycium asterium var. minimum, Gymnocalycium stellatum var. minimum
Scientific Classification
Family: Cactaceae
Subfamily: Cactoideae
Tribe: Trichocereeae
Genus: Gymnocalycium
Etymology
The specific epithet "ragonesei" (pronounced "rag-oh-NEE-see-eye") honors Arturo Enrique Ragonese (1909-1992), an Argentine botanist who collected the type specimen.
Origin
Gymnocalycium ragonesei is native to Argentina.
Description
Gymnocalycium ragonesei is a small cactus with a usually solitary, flattened-globose stem with 7 to 10 ribs lined with clusters of almost hairlike spines. The stem slowly grows, reaching a height of 1 inch (2.5 cm) and a diameter of 3 inches (7.5 cm). The color of the stem varies by season, from grey-green and olive-green to purplish-brown.
The flowers are creamy white with a reddish throat and appear in late spring, remaining open for up to 12 days. They are funnel-shaped and can measure up to 2 inches (5 cm) in length and up to 1.8 inches (4.5 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, growing among shrubs or grasses, while others thrive in complete exposure. Therefore, some plants will need light shading from the sun in the hottest months, but overdoing it will result in the loss of flowers.
The potting medium's balance 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 allow the compost to nearly dry out before rewatering. Watering in the winter months is unwise and unnecessary. The difficult times are spring and autumn.
Those species which produce offsets can be readily propagated by cuttings. Gymnocalycium seeds germinate well when fresh and can be stored for a few years in cold conditions.
See more at How to Grow and Care for Gymnocalycium.
Links
- Back to genus Gymnocalycium
- Succupedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus
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