Soehrensia is a genus of cacti in the family Cactaceae, placed within the subfamily Cactoideae, tribe Cereeae, and subtribe Trichocereinae. The genus was established by the German cactus taxonomist Curt Backeberg in 1938, with its first publication in Blätter für Kakteenforschung 5(6): 7. The type species is Soehrensia bruchii, a large, barrel-forming to clustering cactus native to northwestern Argentina.
Plants in this genus are South American cacti ranging in habit from sprawling or decumbent to columnar forms, with stout ribbed stems bearing prominent areoles and spines. Many species produce large, showy flowers — often white, pink, red, or orange — that emerge from the sides of the stems, a trait shared with the closely related genus Echinopsis. The group spans a broad altitudinal and ecological range across the Andes and adjacent lowlands, from semi-arid scrub to high-altitude grasslands.
The native range covers northern Argentina, Bolivia, northern Chile, Paraguay, and Peru. Several species, particularly the columnar S. spachiana (Golden Torch Cactus), have become widely grown in horticulture around the world and are naturalised in parts of Mexico, southern Africa, and Spain.
The genus has had an unsettled taxonomic history. During the 1970s and 1980s it was lumped into the broader genus Echinopsis Zucc. It was restored as a distinct genus in the 2016 edition of the CITES Cactaceae Checklist. A major phylogenomic study published in 2025 concluded the group should again be treated as a synonym of Echinopsis; Plants of the World Online (Kew) reflects this synonymisation, while GBIF continues to list Soehrensia as an accepted genus with approximately 24–26 species. The number of recognised species varies between 23 and 37 depending on the authority consulted.
Etymology
The genus name Soehrensia was coined by Curt Backeberg in 1938 to honour Johannes Soehrens (died 1934), a Dutch botanist who served as Professor and Director of the Botanical Garden in Santiago de Chile, where he was noted for his expertise in cacti.
Distribution
The natural range of Soehrensia is centred on the southern Andes and adjacent lowlands of South America: northern Argentina (the primary centre of diversity), Bolivia, northern Chile, Paraguay, and Peru. Through widespread cultivation, particularly of the columnar species S. spachiana, the genus has become naturalised in parts of Mexico, southern Africa, and Spain. Specimen records documented in North American herbarium networks include material from Arizona and New Mexico, reflecting cultivated or escaped populations.
Conservation
No species of Soehrensia is listed in the IUCN Global Invasive Species Database, and no invasive or noxious-weed listings were found for the genus. The conservation status of individual species has not been assessed in the sources consulted.
Taxonomy
Soehrensia was established by Curt Backeberg in 1938 (published in Blätter für Kakteenforschung 5(6): 7, GBIF usageKey 7279790). The type species is Soehrensia bruchii. During the taxonomic revisions of the 1970s and 1980s the genus was synonymised with Echinopsis Zucc., under which most of its species were treated for several decades. The 2016 CITES Cactaceae Checklist restored Soehrensia as an independent genus. A 2025 phylogenomic study reversed this again, returning Soehrensia to synonymy under Echinopsis; this treatment is followed by Plants of the World Online (Kew). GBIF (as of 2026) continues to list Soehrensia as an accepted genus. GBIF recognises 26 child taxa: 24 accepted species, one accepted hybrid (S. ×mendocina), and one doubtful hybrid (S. ×allagantha).
