Similar stems in different lineages
An epiphytic way of life arose more than once in cacti. Flattened stems increase the surface exposed to light, and a hanging or spreading habit allows plants to occupy supports and rock ledges. Similar traits may have developed in lineages with different origins. In historical classifications, these similarities contributed to grouping species in the genera Rhipsalis, Lepismium and Pfeiffera. [Korotkova et al. 2010]
Korotkova and colleagues compared sequences of eight chloroplast genome regions in studies of the circumscription of Pfeiffera. Combining molecular data with morphology allowed separation of groups that resembled one another in habit but occupied different positions in the family tree. [Korotkova et al. 2010, methods]
The result for Lymanbensonia
Material of Lymanbensonia brevispina, L. incachacana and L. micrantha (the corresponding Pfeiffera species in older treatments) formed a distinct lineage. In the broader analysis, it was sister to Calymmanthium. The authors reinstated the name Lymanbensonia and described the tribe Lymanbensonieae for both genera. [Korotkova et al. 2010, pp. 159–166]
Inclusion of L. crenata relied on morphology and earlier documentation, because this species was not sequenced. The treatment thus distinguished material directly present in the molecular analysis from a species assigned on other traits. The currently recognised L. choquequiraensis was described later, in 2020. [Korotkova et al. 2010][3-WWW]
What differs between close relatives
| Trait | Calymmanthium | Lymanbensonia |
|---|---|---|
| Habit | Branched shrubs or trees | Smaller plants, erect, spreading or hanging |
| Stem | Several thin, wing-like ribs | Flattened or angular, depending on species |
| Substrate | Terrestrial growth | Terrestrial, rock-dwelling or epiphytic growth |
| Flower bud | Hidden inside the short-shoot covering, which opens before flowering | More typical architecture, with an exposed developing perianth |
The difference in habit encompasses whole-plant size, stem width and use of space. Growth on rock faces in the Sandia valley has been documented in L. micrantha. This is an important detail of the genus's biology, because some species are epiphytic, while this particular field material was rock-dwelling. [Hoxey 2016, pp. 191–192]
Significance of the 2025 classification
De Vos and colleagues included Calymmanthium in an analysis of hundreds of nuclear genes and retained Lymanbensonieae. Lymanbensonia was not included in the new sampling, and its assignment relied on earlier results. The publication therefore provides new context for the tribe's placement while retaining the historical basis for the relationship between the two genera. [de Vos et al. 2025]
In some of the earliest branches of Cactoideae, trees based on different gene sets showed discrepancies. The authors analysed signal concordance among genes. This approach reveals both stable groups and nodes whose exact relationships require further resolution. [de Vos et al. 2025]
Names that allow older papers to be read
The atlas uses the names Lymanbensonia brevispina (formerly Lepismium brevispinum or Pfeiffera brevispina), L. incachacana (formerly Rhipsalis incachacana) and L. micrantha (formerly Cereus micranthus or Acanthorhipsalis micrantha). Historical combinations preserve information about the same material in the history of research. [Korotkova et al. 2010]
The Lymanbensonia profiles describe individual species and their identifying traits. The Calymmanthium profile is complemented by an account of its unusual flower development. [de Vos et al. 2025][Korotkova et al. 2010]
A phylogenetic analysis of Pfeiffera and the reinstatement of Lymanbensonia as an independently evolved lineage of epiphytic Cactaceae within a new tribe Lymanbensonieae
Korotkova N., Zabel L., Quandt D., Barthlott W., A phylogenetic analysis of Pfeiffera and the reinstatement of Lymanbensonia as an independently evolved lineage of epiphytic Cactaceae within a new tribe Lymanbensonieae, Willdenowia, 2010, 40(2):151-172, doi: 10.3372/wi.40.40201
Analyses of eight plastid regions separate the former Pfeiffera into distinct lineages and indicate a relationship between Lymanbensonia and Calymmanthium. The paper includes comparative stem, flower and fruit descriptions, a key to six Pfeiffera species and new name combinations. It discusses variation in Pfeiffera boliviana and method-dependent differences in the inferred relationship of P. miyagawae.
International Plant Names Index
Authorship and publication of botanical names. A nomenclatural register does not determine acceptance of a taxon.
Accessed 2026-10-08.
Phylogenomics and classification of Cactaceae based on hundreds of nuclear genes
de Vos J. M., Eggli U., Nyffeler R., Larridon I., McGinnie C., Epitawalage N., Maurin O., Forest F., Baker W. J., Phylogenomics and classification of Cactaceae based on hundreds of nuclear genes, Plant Systematics and Evolution, 2025, 311(5):28, doi: 10.1007/s00606-025-01948-z
The study analyses hundreds of nuclear genes and their agreement in reconstructing Cactaceae relationships. It presents a revised classification of subfamilies, tribes and genera with morphological descriptions.
Notes on the cacti of the Sandia valley, Puno, Peru and a description of a new species of Echinopsis (Cactaceae)
Hoxey P., Notes on the cacti of the Sandia valley, Puno, Peru and a description of a new species of Echinopsis (Cactaceae), Bradleya, 2016, 34:187-199, doi: 10.25223/brad.n34.2016.a7
The account from the Sandia valley in Peru describes localities, elevations and traits of several cacti. The section on Lymanbensonia micrantha presents rocky habitats, stem structure, pink flowers, the nectar chamber and fruits.
