Genus honouring Francisco Ortega’s family, a Zapotee Indian guide from San Jose Lachiguiri, Oaxaca, Mexico, who discovered the species for MacDougall. Portrait is unknown.
Monotypic genus of low growing plants at first solitary, becoming caespitose, with stems globose to shortly elongated, pale greyish-green. Tubercles arranged spirally, more or less flattened and rhomboid, punctuated, sometimes with a groove. Areoles woolly, bearing a central spine and 7-8 radial spines erect, straight, white with a black tip.
Flowers diurnal, self-sterile or self-fertile according to clones, borne at the axillary base of the upper tubercles, funnelshaped, intense yellow, pollinated by butterflies and bees. Fruits globose to elongated, sunken in the axils of tubercles, dry when mature, floral remains persistent. Seeds globose, with a large hilum, foveolate, brown to black.
The monotypic genus Ortegocactus grows endemically in Mexico at high altitudes, in an extremely limited area, on a hill, at the top of steep limestone rocks, in masses of fallen rocks, on bare soils, among mosses and lichens, between 1600 m and 2500 m in altitude. The unsightly orange spots which sometimes appear on old plants in collections also seen on plants in habitat and are a natural phenomenon which does not affect the growth of plants at all. Only experienced growers like Jurgen Menzel are able to obtain perfect plants (see below).
Currently only one recognised species:
– Ortegocactus macdougallii* Alexander 1961
References: "TAXONOMY of the CACTACEAE" - ISBN 978-84-617-3692-8 (Vol. 2)