living rock cactus

Kotschoubey paid a fortune

This living rock cactus was first described in 1842 by the botanist Lemaire. Ariocarpus kotschoubeyanus is named after Prince Kotschoubey who paid a fortune, his own weight in gold, for one of the three first examples to come into Europe in the 19th century. This species does not look like a typical cactus. Thorns are lacking and it is grey-green to grey-brown in colour with a warty form. It grows on average to about 7 cm, is strongly flattened and composed of triangular bulges, the so-called tubercles. The flowers are purple in colour, sometimes white, 3-5 cm on diameter. Local people use the living rock cactus as a painkiller for bruising. It is an immensely popular species amongst cactus enthusiasts.

Ecology and habitat

Living rock cactus is a geophyte: during the dry season the plant shrivels and retracts into the calcareous soil on which it grows. It has a taproot in which reserves are stored to enable the plant to survive drought. It is native to Mexico and grows at an altitude of 1000-1400 m in a large area that stretches from Coahuila in the north to Queretaro in the south - a distance of about 600 km. The plants grow in small, isolated populations in calcium rich, stony, loam soils.

Threats

Although there are an estimated 100,000 mature plants, the living rock cactus is considered threatened because the populations are isolated from one another and the number of populations is decreasing. Threats also come from the construction of buildings and infrastructure. Its habitat is often good agricultural land. The local people collect this plant for medicinal purposes. It appears on Appendix 1 of CITES and so wild plants and seed of this species are not to be traded. They are commonly cultivated and the seed can easy be found on sale.