Trichocereus pachanoi reclassified as macrogonus var pachanoi

[saguaro]

This was news to me. Did anyone else know this?

 

Supposedly Trichoceres pachanoi aka Echinopsis pachanoi was reclassified as Trichocereus macrogonus var pachanoi (syn. Echinopsis macrogonus var pachanoi) in 2023.

 

https://powo.science.kew.org/taxon/77125731-1#synonyms

 

 

Edited February 7 by saguaro

[fyzygy]

Yep.

 

Edited February 7 by fyzygy

[saguaro]

it would be interesting if there was a DNA barcode for Trichocereus / Echinopsis and these classifications were phylogenetically informed.

 

Can't imagine anyone would fund that any time soon though

Edited February 7 by saguaro

[trucha]

No DNA barcode but there has been ongoing genetics work in this area for a few years now.

 

This one is easy enough to look up. Google Boris Schlumberger & Renner [MOLECULAR PHYLOGENETICS OF ECHINOPSIS (CACTACEAE): POLYPHYLY AT ALL LEVELS AND CONVERGENT EVOLUTION OF POLLINATION MODES AND GROWTH FORMS] and also Albesiano & Kiesling [Identity And Neotypification Of Cereus Macrogonus, The Type Species Of The Genus Trichocereus (Cactaceae)] and Albesiano & Terezas [Cladistic Analysis Of Trichocereus (Cactaceae: Cactoideae: Trichocereeae) Based On Morphological DATA And Chloroplast Dna Sequences]

 

However Albesiano's peruvianus came from a plant someone had collected in Bolivia, submitted at La Paz as a lageniformis and was then renamed peruvianus by Albesiano. They appear to have *looked at* Britton & Rose's sad collection sheet but did not include any Peruvian material in their actual analysis of peruvianus (among other problems such as declaring a plant someone had collected from near Tarma Peru to be both a bona fide macrogonus and their Neotype) so Albesiano's work is also easily attacked.

David Hunt accepted their proposed revision anyway and even restored Trichocereus as the genus for these plants but since his death Echinopsis is again regarded to be accepted genus name (despite there being no question that it is polyphyletic).

 

More work is ongoing by other workers. Genetics work is getting affordable.