Acanthocalycium rhodotrichum

Acanthocalycium rhodotrichum is a species of Acanthocalycium found in Argentina, Bolivia, Brazil, Paraguay, and Uruguay.

Description
Acanthocalycium rhodotrichum usually grows in groups with erect or ascending, cylindrical, dull green shoots that reach heights of 30 to 80 cm with a diameter of up to 12 cm. There are eight to 18 low ribs that are somewhat wavy. The areoles on it are 1.5 to 2.5 cm 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 2 cm long. The spread and slightly curved four to eight radial spines are up to 2 cm long. The funnel-shaped white flowers open at night. They grow up to 15 cm long.

Distribution
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.

Subspecies
Recognized subspecies:

Taxonomy
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.