Obregonia denegrii
Sometimes called artichoke cactus, this species is a single-stemmed plant that has tubercles that layer like an artichoke or pinecone. It is related to the famous Ariocarpus plants. It will grow about half a foot tall and wide and eventually develop a wool-like tuft at the top of the plant. White flowers with yellow throats appear in summer which produce fruits that will be buried in the wool. The fruits are usually white with the old, withered flowers attached at the top.
Since these are small plants, they are best kept in a container, in well-drained cactus soil. Summer growing, they can be watered when dry throughout the warm season. Keep plants drier in winter. They are hardy to about 20°F if kept dry.
Obregonia is a monotypic genus of cacti, containing the species Obregonia denegrii. The species is endemic to the state of Tamaulipas in Mexico.
The genus Obregonia is named after Álvaro Obregón, a general in the Mexican Revolution. The species, denegrii, is named after Ramon P. De Negri, who was the Minister of Agriculture of Mexico when the cacti was first described by Alfred Frec in 1923.
This species has a very small geographic range near Ciudad Victoria in the Valley of Jaumave, Tamaulipas, Mexico. The population continues to decrease due to collecting.
Obregonia denegrii in Tamaulipas, Mexico, blooming. Photo by José Francisco Gómez Rodríguez, iNaturalist
A colony of Obregonia denegrii, also blooming. Photo by sergioniebla, iNaturalist
A mature plant with the characteristic tuft of hair on tip, photo by Ad Konings, iNaturalist