Aylostera BUININGIANA - Buining's aylostera, Aylostera buiningiana, Rebutia.
Aylostera is a genus of plants in the cactus family (Cactaceae), comprising, according to various data, from 10 to 30 species. In nature, they grow high in the mountains, in crevices and hollows of rocky slopes, and are accustomed to sharp diurnal temperature drops.
The genus is very close to rebutias, but differs from them in cylindrical stems in adult plants, bristles on the floral tube, and a style fused with the tube for half its length. Some authors consider Aylostera a subgenus of Rebutia altogether, so in catalogs the same plants are found under both names.
The plants are small, up to 6 cm (2.4 in) across, ovoid or cylindrical, densely covered with thin spines and profusely forming lateral shoots. There are 11-25 ribs, divided into small tubercles. The spines are white, thin, bristle-like, about 0.5 cm (0.2 in) long, with central ones longer, up to 2 cm (0.8 in). The flowers are solitary, funnel-shaped, orange or red, up to 4 cm (1.6 in) across.
Buining's aylostera is a small globose cactus up to 5 cm (2 in) across. The stem is solitary, offsets appear very rarely, and in this the species differs noticeably from most relatives that readily form clumps.
It blooms surprisingly early, often as early as the second year of life. The flowers are 3-4 cm (1.2-1.6 in) across, orange-pink, with neatly rounded petals, each lasting about three days. When grown in open sun, the coloration fades, and on the second or third day the flowers turn light orange.