Family: Cactaceae
Common Name: Chin Cactus

This large group of South American cactuses is very popular and their ease of culture makes them a good choice for novice growers. All species are small, and all are characterized by a chin-like protuberance below the areoles, hence their common name. The well-defined ribs are notched into tubercles. The spines vary from weak to very strong. The large, tunnel-form, day-time flowers are self-sterile, and range in colour from white through yellow to green and red.

Species

G. andreae is a flattened, globe-shaped, dark green plant, with warty ribs. Large, sulphur yellow flowers appear at the crown in the spring and the summer.

G. baldianum is a small, soli­tary, globe-shaped, gray cactus with a depressed apex and rounded ribs. The wine red flowers are 25 cm (10 in) in diameter.

G. mihanovichii has a striped body, a number of greenish flowers and whorls of brownish yellow spines. There are unusual natural varieties in colours of red or yellow which are very attractive.

G. multiflo­rum is a broadly globe-shaped, blueish green, ribbed plant, with deep furrows betsveen the ribs, and comb-like spines. The short, pink flow­ers are about 25 mm (1 in) in diameter.

G. quehlianum, a flattened, blueish green plant, has white flowers with a red-coloured throat.

G. saglionis is the largest of the species, and it is also one of the most attractive. It has thick, rounded tubercles, curved, reddish spines and white to pink, bell-shaped flowers.

Cultivation

In cool and cold climates, grow these cactuses in an intermediate greenhouse or con­servatory, in pots of cactus compost. Plants need maximum light but shade them from direct, strong sun. Water normally in the growing period, but withhold water in the winter resting period. Propagate in spring from seed, germinat­ing them at 24°C (75°F), or from offsets.

Climate

Zone 10.