Austrocylindropuntia is a genus of cacti in the family Cactaceae, order Caryophyllales, comprising eight to eleven species of columnar to cylindrical spiny succulents native to the Andes and adjacent regions of South America. The genus was established by the German cactus specialist Curt Backeberg in 1938, segregated from the large and heterogeneous genus Opuntia on the basis of their distinctly cylindrical (rather than flattened) stem segments, a character reflected in the genus name. Members are sometimes called "cylindropuntias" or informally grouped with the cholla-like cacti.
Plants in this genus are generally erect, branching shrubs or small trees with cylindrical, jointed, tuberculate stem segments covered in clusters of sharp spines and, in some species, a dense wool of white hair. The rudimentary leaves present on young growth are short-lived. Flowers are typically red, orange, or yellow, arising near stem tips, and fruit is fleshy and often proliferous — capable of producing new stems from the fruit body itself, a key dispersal adaptation.
The genus is native to the Andean highlands and Pacific slopes of South America, with species recorded in Argentina, Bolivia, Colombia, Ecuador, and Peru. Several species have become widely naturalized outside their native range, particularly in the Mediterranean basin, parts of Africa, and Australasia, where they can form dense thickets and are considered invasive weeds in some regions. Austrocylindropuntia subulata, the most widely cultivated species, is grown globally as an ornamental and is among the most frequently naturalized members.
Within Cactaceae, Austrocylindropuntia belongs to the subfamily Opuntioideae. Molecular and morphological studies have supported its separation from Opuntia sensu stricto, and several synonyms — including Andinopuntia, Peruviopuntia, and Trichopuntia — reflect earlier attempts to further subdivide what Backeberg originally circumscribed.
Etymology
The genus name Austrocylindropuntia combines the Latin austro- ("southern") with Cylindropuntia (the North American chollas), reflecting both the southern (South American) distribution of these plants and their cylindrical stem segments — distinguishing them from the flattened-pad opuntias. The genus was formally named by Curt Backeberg in 1938.
Distribution
All species are native to South America, with the center of diversity in the Andes and Pacific slopes of Argentina, Bolivia, Colombia, Ecuador, and Peru. Several species have naturalized widely outside their native range, including in Mediterranean Europe, the Canary Islands, Madeira, parts of sub-Saharan Africa, and Australasia (New South Wales, Victoria, New Zealand).
Taxonomy Notes
Austrocylindropuntia was segregated from Opuntia by Curt Backeberg in 1938 and published in Blätter für Kakteenforschung. The genus belongs to the subfamily Opuntioideae within Cactaceae. Several junior synonyms have been proposed — including Andinopuntia Guiggi, Banfiopuntia Guiggi, Peruviopuntia Guiggi, Pseudotephrocactus Frič & Schelle, and Trichopuntia Guiggi — but these are not accepted in current treatments. Plants of the World Online recognizes eight species; GBIF's backbone recognizes eleven descendants.
Cultivation
Several species of Austrocylindropuntia are cultivated as ornamentals, particularly A. subulata (Eve's needle cactus), which is grown worldwide for its bold architectural form. They are suited to warm, dry climates and well-drained soils, and tolerate drought once established. In frost-prone areas they are grown in containers or cool glasshouses. Their prolific vegetative reproduction via detachable stem segments makes them easy to propagate but also contributes to their invasiveness outside the native range.
