Acanthocalycium rhodotrichum is a species of Acanthocalycium found in Argentina, Bolivia, Brazil, Paraguay, and Uruguay.[1]
Acanthocalycium rhodotrichum usually grows in groups with erect or ascending, cylindrical, dull green shoots that reach heights of with a diameter of up to . There are eight to 18 low ribs that are somewhat wavy. The areoles on it are apart. Yellowish thorns with a brown tip emerge from them. The single central spine, which can also be absent, is bent slightly upwards and is up to long. The spread and slightly curved four to eight radial spines are up to long. The funnel-shaped white flowers open at night. They grow up to long.[2]
Acanthocalycium rhodotrichum is widespread in the Brazilian state of Mato Grosso do Sul, in Paraguay and in northeast Argentina at altitudes of up to 500 meters.[3]
Recognized subspecies:[1]
| Image | Subspecies | Description | Distribution |
|---|---|---|---|
| Acanthocalycium rhodotrichum subsp. chacoanum | Has twelve to 18 ribs and seven to eight marginal spines. The first description as Echinopsis chacoana by Bohumil Schütz was published in 1949. Boris O. Schlumpberger introduced the species as a subspecies to Acanthocalycium rhodotrichum in 2021.[4] | Common in the Chaco vegetation in Paraguay. | |
| Acanthocalycium rhodotrichum subsp. rhodotrichum | Distributed deep in the Chaco vegetation in Paraguay and the Argentine provinces of Chaco, Formosa, Corrientes, Entre Ríos, Santiago del Estero and Santa Fe. | ||
The first description as Echinopsis rhodotricha by Karl Moritz Schumann was published in 1900. Boris O. Schlumpberger placed the species in the genus Acanthocalycium in 2012.