Name and species circumscription
Austrocactus coxii is the name accepted in Plants of the World Online, checked on 10 October 2026. The accepted subspecies are A. coxii subsp. coxii, subsp. colloncurensis and subsp. longicarpus. Each description retains its appropriate scope. The 2025 revision combines the first two in one species, while distinguishing the third as A. longicarpus. [2-WWW] [Böhnert et al. 2025, taxonomic record and species description in the 2025 revision]
Podgatunek nominatywny
Austrocactus coxii subsp. coxii forms branched, creeping or spreading stems, sometimes clumps. The stems are up to 15 cm, occasionally 30 cm long, and up to 5 cm in diameter. They produce adventitious roots. Eight to ten ribs are divided into elongated tubercles. Slightly sunken areoles on young growth bear dense whitish wool. The central spines, usually 3–4, are straight and stronger than the 7–11 radial spines. [Böhnert et al. 2025, p. 409]
The broadly funnel-shaped flower measures around 6 × 4.5 cm. The perianth base is yellow, and the upper tepal portions may be brown, orange, reddish or yellow. The stigma has around 13 yellowish lobes. The spherical, green fruit, around 15 × 15 mm, is covered with scales, wool and soft bristles. It dries and opens irregularly from the base. Greyish-brown to black seeds measure around 3 × 2 mm. [Böhnert et al. 2025, p. 409]
The revision describes sites on rocky outcrops of the Patagonian pampa at the Andean foothills in southern Neuquén, western Río Negro and northern Chubut. The name A. gracilis, based on plants from the eastern side of Lake Nahuel Huapi, is a synonym of the nominate subspecies in both this treatment and POWO. [Böhnert et al. 2025, p. 409] [2-WWW]
Podgatunek colloncurensis
Austrocactus coxii subsp. colloncurensis (formerly A. colloncurensis) has branched, spreading stems with adventitious roots. Their length is usually around 8 cm, sometimes up to 20 cm, and their diameter up to 5 cm. There are 5–9 ribs, 4–7 central spines and 5–10 radial spines. The flower is around 3.5 cm long and 4.5 cm in diameter. The inside of the perianth is pale lemon-yellow, and the outside beige to pink. [Böhnert et al. 2025, p. 409] [2-WWW]
The roughly nine stigma lobes are mostly violet, sometimes yellow. The fruit is distinctly elongated, around 10 × 30 mm, green to dark green, woolly and bristly. It opens from the base. Rocky-outcrop sites include Collón Curá, southern Catán Lil and northern Pilcaniyeu. Genomic analysis confirmed closeness to the nominate subspecies, with weak genetic separation of the two forms. Subspecies rank retains their recognisable morphological differences. [Böhnert et al. 2025, p. 409, 411]
Subspecies longicarpus and the difference between classifications
Austrocactus coxii subsp. longicarpus (called A. longicarpus in the revision) has upright, solitary or branching stems, around 15 cm long and up to 6 cm in diameter. There are 8–10 ribs, 1–3 central spines and 6–9 radial spines. The narrow funnel-shaped flower, around 4.5 × 4.5 cm, is pale to dark pink. The stigma has 5–7 pale yellow lobes. [Böhnert et al. 2025, p. 406] [2-WWW]
The elongated cylindrical fruit measures around 2.5 cm long and 1 cm in diameter. It is green to reddish green, sparsely woolly and splits lengthwise after drying. The revision places plants north and south of Zapala and westwards to Primeros Pinos, at elevations of 1000–1400 m. The pink flower, small number of pale stigma lobes and longitudinal fruit splitting distinguish this taxon from the nominate subspecies. [Böhnert et al. 2025, p. 406–407]
In the ddRADseq analysis, plants identified as A. longicarpus fell within section Hiberni, separate from subspecies coxii and colloncurensis in section Coxiani. The revision's authors therefore rejected its inclusion in A. coxii. POWO still accepts subspecies rank. The taxonomic difference remains explicit, and the results of the longicarpus study apply specifically to this group of plants. [Böhnert et al. 2025, p. 389–391, 401, 406–407] [2-WWW]
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]
Synonyms and names in the literature
Austrocactus colloncurensis · Austrocactus longicarpus · Austrocactus coxii subsp. colloncurensis · Austrocactus coxii subsp. longicarpus · Austrocactus coxii subsp. coxii · Austrocactus gracilis · Echinocactus coxii · Austrocactus intertextus [2-WWW]