Gymnocalycium OENANTHEMUM x HORSTII - Wine-flowered chin cactus x Horst's chin cactus, Gymnocalycium oenanthemum x horstii.
Gymnocalycium is a genus of plants in the family Cactaceae, comprising about 70 species widely distributed in South America, especially in Argentina, Brazil, Paraguay, Uruguay, and Bolivia at altitudes of 800-3000 m (2,600-9,800 ft) above sea level, on granitic and clayey soils.
Gymnocalyciums are valued for the graceful contours of their stems, which are usually globose and flattened, with a diameter of 4 to 15 cm (1.6 to 5.9 in), while their height is approximately half of the diameter. The primary stem coloration varies from grayish-green to brownish-green, sometimes with an almost gray or almost brown tint. Some cultivars feature unusual red or yellow stems devoid of chlorophyll; such plants are capable of developing only when grafted. The stems are generally distinctly ribbed, with tubercles located on the ribs. The spines are moderately stiff, often recurved.
The plants are valued for their showy flowering. The flowers are funnel-shaped with a short tube, form from areoles at the apex of the stem, and open during the day. The flower tubes in representatives of this genus, unlike most other cacti, are devoid of bristles and hairs and are covered with smooth scales. Coloration varies from white and pink to red, yellow, greenish, or brownish-yellow. The fruits are oblong, juicy or dry, containing large black seeds with a texture characteristic of the genus.
Gymnocalycium oenanthemum x horstii is a hybrid with a dense globose body reaching 7-10 cm (2.8-3.9 in) in diameter. The surface is matte, dark green with a bluish tint. The ribs are broad and gentle, the areoles are large, and the spines are straight or slightly curved, white or cream, neatly bent away from the body.
It blooms in the summer period. The flowers are large, funnel-shaped, deep pink or lilac, up to 6 cm (2.4 in) in diameter. They may exhibit shades characteristic of one of the parent species. The fruits are green, oval, with a smooth skin. The seeds are large and black.