Scientific taxonomy article
Accepted name and publication history
The accepted name in the current Kew backbone is Cereus forbesii C.F.Först.. Förster published the name in 1846 on page 398 of Handbuch der Cacteenkunde. IPNI records the more explicit nomenclatural authorship Hort.Berol. ex C.F.Först., while POWO displays C.F.Först. for the accepted name. IPNI supplies nomenclatural authorship and place of publication, while current acceptance, synonymy, and native distribution follow POWO's taxonomic opinion.12
The name is not a new combination transferred from another genus, so it has no parenthetical basionym author. The shorter POWO authorship and extended IPNI authorship are presentations of the same name, not separate species.
Taxon boundary and infraspecific treatment
In the Kaktüs Doktoru backbone, the species is a child of the genus Cereus. Kew lists no accepted subspecies or variety on the current species page. This package updates only the canonical species node and its linked botanical-dictionary record; it does not flatten accepted subordinate ranks into species synonyms, rewrite the genus node, or alter the product.
Diagnostic characters
The wild species is treated as a tree-like columnar Cereus of South American desert and dry shrubland, with green to bluish stems and pronounced ribs. Species identity cannot be inferred from straight or spiral growth alone; flowers, fruit, areoles, and provenance also matter. These characters must be assessed together. A product photograph is not an herbarium voucher, and cultivation may alter stem colour, spine density, and growth direction.
“Spiralis” is absent from POWO’s accepted species, accepted infraspecific, and 11-name synonym lists. That absence supports treating it as a horticultural growth-form label rather than a canonical taxonomic rank; its origin and heritability require separate product- or nursery-level documentation.13
Phylogenetic context
The 2023 genus-level phylogeny investigated relationships within Cereus with hundreds of captured nuclear orthologues and a coalescent framework, demonstrating why traditional appearance-based circumscriptions require genomic testing.4 A 2025 family-wide phylogenomic study then reassessed the Cactaceae backbone and classification using hundreds of nuclear genes.5 These studies do not by themselves rename this species; they warn against inferring close relationship from one conspicuous stem or spine character.
Native distribution and conservation
Kew records the native range as Bolivia, Paraguay, and north-eastern to north-western Argentina.1 POWO describes the species as a succulent tree of desert or dry-shrubland biomes. Its broad but dry-region distribution supports high air movement and rapid drying in cultivation rather than persistent moisture. The stored conservation category is LC.6 The LC assessment is published by IUCN under Cereus hankeanus, a name treated by Kew as a synonym, rather than under the accepted name itself. Metadata will retain that assessed-name distinction; commercial stock is not evidence of wild-population status.
Synonymy and retrieval
Kew accepts 11 synonyms at the species node: Piptanthocereus forbesii is the homotypic name; C. cochabambensis, C. comarapanus, C. hankeanus, C. huilunchu, and several Piptanthocereus combinations form the broader synonym surface. These are not canonical routes; they document nomenclatural history and support retrieval of older literature. “Spiralis” is absent from this list and will not be inserted as a synonym.1
References
- Plants of the World Online. “Cereus forbesii C.F.Först.” Royal Botanic Gardens, Kew. Accessed: 2026-08-04. https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:130203-1 ↩
- International Plant Names Index. “Cereus forbesii Hort.Berol. ex C.F.Först.” Accessed: 2026-08-04. https://www.ipni.org/n/130203-1 ↩
- Plants of the World Online. “Cereus forbesii C.F.Först. — accepted taxonomy and synonym list.” Royal Botanic Gardens, Kew. Accessed: 2026-08-04. https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:130203-1 ↩
- Taylor, N. P. et al. “A phylogeny of Cereus (Cactaceae) and the placement and description of two new species.” Taxon. https://doi.org/10.1002/tax.13103 ↩
- de Vos, J. M. et al. “Phylogenomics and classification of Cactaceae based on hundreds of nuclear genes.” Plant Systematics and Evolution 311:28 (2025). https://doi.org/10.1007/s00606-025-01948-z ↩
- IUCN Red List of Threatened Species. “Cereus hankeanus.” https://www.iucnredlist.org/species/152176/121461728 ↩
- World Flora Online. “Cereus forbesii C.F.Först.” Accessed: 2026-08-04. https://www.worldfloraonline.org/taxon/wfo-0000597105 ↩
