The plants in this sub-tribe are spherical or elongated. As a rule they are small plants of low habit. Theare developed singly on the areoles near the centre of the crowns, and are mostly funnel-shaped with a short tube. Many of the genera are heavily spined.
ARIOCARPUS. These are plants with a tap, of low growth, round, flat-topped, and spineless. The tubercles have the appearance of thick triangular fleshy . There are 7 species in the genus.
Ariocarpus retusus. Mexico. Forms a somewhat flattened grey-green to reddish rosette, about 5 inches in diameter. The crown of the plant is very woolly. The tubercles are more or less triangular; they are arranged in rosette form, and generally have a woolly, horny point. Theare white, with pink on the outside, and arise from the axils of younger tubercles.
Ariocarpus fissuratus. Texas and Mexico. The plant owes its name to its more or less warted and split exterior. It is approximately circular in shape and rarely exceeds 6 inches in diameter. The triangular tubercles form a rosette. The flowers are white to purple. Because of the plant s dull grey to brownish colour, which makes it difficult to distinguish from rocky surroundings, it is often called the living rock.