Gymnocalycium pflanzii (Vaupel) Werderm.
Echinocactus pflanzii, Gymnocalycium pflanzii subsp. pflanzii
Gymnocalycium pflanzii is a small cactus with a flattened spherical stem with 10 to 12 tuberculate ribs and wooly areoles with clusters of stiff, curved spines. The stem can grow up to 4 inches (10 cm) tall and 6 inches (15 cm) in diameter, solitary or slowly clustering. It is green, tinged orange-purple when exposed to full sun. The spines are initially blackish with a brown base but turn gray-pink to whitish-brown with a black tip with age. Each areole bears 1 or 2 central and 5 to 9 radial spines.
The flowers are funnel-shaped with carmine throat and white petals, each with a brownish-green midrib. They can reach up to 2 inches (5 cm) in diameter. The fruits are spherical, measuring up to 0.8 inches (2 cm) in diameter, carmine when they ripen, and contain cherry-red pulp and dark brown to black seeds.
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 entirely 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.
Watering in the summer months, while the plants are growing well, can be frequent (weekly for small plants in small pots) but always allows the compost to nearly dry out before rewatering. Watering in the winter months is unwise and, indeed, 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.
- Back to genus Gymnocalycium
- Succupedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus
Click on a photo to see a larger version.