Austrocactus hibernus

Name and species circumscription

Austrocactus hibernus is the name accepted in Plants of the World Online, checked on 10 October 2026. POWO accepts two subspecies, the nominate hibernus and robustior. In older collections, the nominate subspecies was sometimes confused with A. philippii. The 2025 revision separates these species using nomenclatural material and plant features. [2-WWW] [Böhnert et al. 2025, taxonomic record and species description in the 2025 revision]

The nominate subspecies and adventitious roots

Austrocactus hibernus subsp. hibernus has branched, creeping, elongated and often slender stems, around 10 cm long and 2–3 cm in diameter. It produces adventitious roots. The green epidermis can redden with sun exposure. Seven or eight ribs divide into elongated oval tubercles. The areoles are covered with pale yellow felt. [Böhnert et al. 2025, p. 403]

The one to four central spines cannot always be clearly distinguished from the others. The uppermost usually bends irregularly upwards. Five to eight radial spines spread sideways. The bell-shaped flower is around 5.5 cm long and in diameter. The perianth is golden brown to copper-orange, sometimes golden yellow, and the stigma has 7–10 yellow to pale yellow lobes. [Böhnert et al. 2025, p. 403]

The green, barrel-shaped fruit grows to 2 cm long. It is finely hairy, succulent and mucilaginous inside, and opens irregularly. The dull black seeds resemble a comma and measure around 2.25 × 1.75 × 0.75 mm. The succulence of the mature fruit distinguishes the species from many members of the genus whose fruits dry out. [Böhnert et al. 2025, p. 403]

Podgatunek robustior

Austrocactus hibernus subsp. robustior has stouter creeping stems, up to 20 cm long and around 3 cm in diameter. Seven to nine ribs divide into rounded tubercles, and the areoles bear dense cream-coloured felt. There are four central spines, rigid and awl-shaped. There are 9–14 radial spines, more than in the nominate subspecies. [Böhnert et al. 2025, p. 406] [2-WWW]

The funnel-shaped flower, around 4.5 × 4.5 cm, has golden-yellow to orange tepals. The stigma divides into 6–8 light yellow lobes. The oval fruit, around 2.5 cm long and 1.5 cm in diameter, is olive green to slightly reddish brown, loosely covered with white bristles and very succulent. It opens irregularly. The black, dull seeds measure around 2.5 × 2 mm. [Böhnert et al. 2025, p. 406]

Sheltered sites and grazing pressure

In the revision, the nominate subspecies occurs on the Chilean side of the Andes in the Maule region and on the Argentinian side in the Minas department of Neuquén and Malargüe in Mendoza. It occupies sheltered places, usually beneath stones or small shrubs, near hollows and streams. This description is broader than the species' main range entry in POWO and derives from specific specimens and observations by the revision's authors. [Böhnert et al. 2025, p. 403, 406] [2-WWW]

Subspecies robustior was described from rocky slopes at the southwestern foot of the Cordillera del Viento, in the southern part of the Minas department. The revision's authors indicate strong pressure from goat overgrazing and very few plants at known sites. This is the source's field assessment of a threat, without a formal IUCN category assigned here. [Böhnert et al. 2025, p. 406]

Cultivation in an archival review

A review from Konrad Szychowski's private archive recommends a cool, dry rest at 0–5°C, sparing watering and ventilation for the group discussed. It considers propagation from offsets easier than sowing. The range of 0–5°C describes the recommended rest under cover. The material did not determine the species' frost-hardiness limit. [Sukulenty b.d.a, pp. 4–6]

Related articles

Materials from the author's archive

The species also appears in Konrad Szychowski's private material archive. [Romulski b.d., file p. 4]