Name and species circumscription
Austrocactus implexus is the name accepted in Plants of the World Online, checked on 10 October 2026. The species was described in 2025. The older designation Austrocactus intertextus sensu Spegazzini (1926) referred to these plants through misapplication of the name. The proper name A. intertextus from 1923 belongs to the history of A. coxii. [2-WWW] [Böhnert et al. 2025, taxonomic record and species description in the 2025 revision]
A stout stem and pale spines
The plant usually has a solitary stem and sometimes branches. The stem is upright and stoutly columnar, up to 25 cm long, usually 4–5 cm and sometimes up to 10 cm in diameter. Ten or eleven distinct ribs bear small, only slightly projecting tubercles. Oval areoles, around 8 × 12 mm, have white felt on young growth. [Böhnert et al. 2025, p. 399]
Four to five central spines are smooth and needle-like, with a thickened base. Around ten radial spines spread in pairs. The authors indicate long spines without distinct pigment as a feature distinguishing the plant from its closest relatives. Stem dimensions and colour need to be considered together with the flower and specimen origin. [Böhnert et al. 2025, p. 399]
The flower and dry fruit
The funnel-shaped flower is around 5 cm long and similar in diameter. The tepals are lanceolate and pointed, pastel pink or yellowish. The style and 10–18 stigma lobes are purple. The green pericarpel bears scales, soft white hairs and few bristles. [Böhnert et al. 2025, p. 399]
The spherical fruit, around 12 × 12 mm, is green, with white wool and a small number of soft bristles. On ripening, it dries and opens irregularly. Seeds are blackish grey, curved and flattened, around 2.25 × 2 mm. Plants raised from seed retained the set of morphological features assigned to the species. [Böhnert et al. 2025, p. 399]
Contact zone and the origin hypothesis
The range described in the revision includes rocky areas of southern Río Negro and northern Chubut. It lies between the main ranges of A. bertinii and A. aonikenkensis. The type material was selected from near Talagapa, linking the new name to historical information on plants from that locality. [Böhnert et al. 2025, p. 399]
The maximum-likelihood analysis placed the species closer to A. bertinii, and the coalescent analysis closer to A. aonikenkensis. Together with its distribution and the stability of offspring traits, this led the authors to hypothesise an established hybrid origin. The study did not provide a separate admixture test determining the genomic contributions of the presumed parents. Species recognisability and uncertainty about its origin describe different aspects of the same lineage. [Böhnert et al. 2025, p. 388–391, 399]
Related articles
Synonyms and names in the literature
Austrocactus intertextus sensu Spegazzini (1926) [2-WWW]