Obregonia denegrii.

One genus and one species of cactus, so majestic and dignified is its appearance that it is known as the ‘TEIKAN’.

This is a very rare cactus and one of the most popular cacti, partly because of its beautiful rosette shape.

Habitat

Obregonia denegrii is a very rare cactus, found only in a very small area around Ciudad Victoria, Mexico, growing in shady rock crevices.

source：https://uk.inaturalist.org

Features

It is characterised by stems with large triangular nodules with a pronounced rosette shape.

Artichoke stems are dark green in colour, with spines growing from small spinous loci at the apex of each node.

Diameter reaches 15 cm.

Flowers are white or slightly pink, with long, narrow petals that bloom from areas covered with whitish downy hairs.

source：https://uk.inaturalist.org

Genus

Obregonia denegrii is a single species of cactus in one genus.

A very rare plant, sometimes called Ariocarpus de Negri or Strombocactus de Negri because it is related to Ariocarpus and Strombocactus.

Not only that, but Obregonia denegri is also considered to be a peyote of one species, due to the internal presence of alkaloids similar to those of the Lophophora genus and the mild psychotropic effects associated with them.

Farming

Growing Obregonia denegrii is not easy.

The most common risk is plant rot.

Attention should therefore be paid to the colour of the nodules.

If the tips start to darken, the amount of water needs to be reduced.

Location: keep in a well-ventilated area.
Temperature: requires an average warm climate, but will tolerate temperatures as low as a few degrees below freezing for short periods, as long as the growing medium is dry.
Watering: water generously in spring and summer, but gradually reduce watering in autumn and cut off completely with the onset of winter.
Soil: Use a mixture of sand, gravel and peat or use cactus soil.
Fertiliser: Apply a cactus-specific fertiliser once a month during the growing season.
Repotting: slow-growing and of moderate size, so repotting is not necessary.Try to select a deep pot to allow the roots to settle and grow well.
Reproduction: reproduces by seed.

source：https://uk.inaturalist.org