Scientific Name
Gymnocalycium saglionis (F.Cels) Britton & Rose
Common Names
Giant Chin Cactus
Synonyms
Gymnocalycium saglionis subsp. saglionis, Echinocactus saglionis, Brachycalycium tilcarense, Echinocactus hybogonus, Gymnocalycium saglione, Gymnocalycium tilcarense
Scientific Classification
Family: Cactaceae
Subfamily: Cactoideae
Tribe: Trichocereeae
Genus: Gymnocalycium
Description
Gymnocalycium saglionis is a cactus with a solitary, spherical, more or less flattened stem that slowly grows up to 3 feet (90 cm) tall. The stem is up to 16 inches (40 cm) in diameter and range in color from dull-green to blue-green. Spines are yellowish-brown, reddish, or white, becoming grey with time and up to 1.6 inches (4 cm) long. Flowers are white or pinkish with a red throat, up to 1.4 inches (3.5 cm) long, and often appear more than one simultaneously. Fruits are spherical, reddish or dark pink with tiny, shiny black-brown seeds.

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 a light shading from the sun in the hottest months, but to overdo, this will result in 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.
Watering in the summer months, while the plants are growing well 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
Gymnocalycium saglionis is endemic to Argentina.
Links
- Back to genus Gymnocalycium
- Succupedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus