Trichocereus Pachanois and peruvianas Both Classified as Echinopsis Pachanois?

[Guest Mesqualero]

When did this happen? I emailed The Cactus Garage about trichocereus pachanois and peruvianas and i got this back :

"T.pachanoi and peruvianus are now classified both as Echinopsis pachanoi.   See Jeff Nugent's book "Agave & Cacti."

Can someone fill me in on what this means?

I'm not all up to speed on taxonomy but i thought they were two completley different things...

Also.... I started this in the wrong forum..... if one of the mods once to snip it out and stick it in the cacti forums that would be lovely

[This message has been edited by Mesqualero (edited 07 February 2002).]

[Torsten]

well, we knew that Trichocereus was included in Echinopsis, but I wasn't aware the peruvianus is now the same as pachanoi.

[Guest Mesqualero]

So what do you think? I'm pretty confused...

I just want to know what to call which so i can order the one i want....

[Guest wira]

The transfer of Trichocereus into Echinopsis is a dodgy issue that was sneaked in by some taxonomists who did very little study to back it. It seemed more a move of convenience than one of rationality. Although Trichocereus could arguably be considered a subgenus of Echinopsis, calling them all Echinopsis only confuses matters more. This is especially because of the poor care taken in the transferral of names. Many things were made synonymous without any real study or consensus from botanists, mainly [it seems] just the work of Friedrich & Rowley, which I've been told was based mainly on seed morphology rather than study of actual plants. Also T. bridgesii is not the same as Echinopsis bridgesii, and things like that

As far as T. pachanoi = T. peruvianus, I think this was a move made by Ritter, as far as that he described T. peruvianus as being simply a form of T. pachanoi [as T. pachanoi forma peruvianus Ritter]. It's worth mentioning that his taxonomic work is taken with a few grains of salt by many people in the field of cactus botany [likewise with Backeberg, though Backeberg was more liked as a person I think, whereas I've heard Ritter wasn't too popular - unfortunately these things DO sometimes play a role in how taxonomy is established]. However he is not the only one to note that T. pachanoi and T. peruvianus intergrade smoothly in the wild [as do many closely related Trichocereus spp.] - that part of it does seem to be accurate. To say that they are all T. pachanoi might be stretching it a bit, in my opinion. It certainly does little to help people identify their cacti in a way that seems to make sense. We still have a very poor picture on this but it will be interesting, hopefully, to see if DNA sequencing of Trichocereus populations gives any leads.

Anyway, I don't think I've seen anything in the literature to extend all that to say T. pachanoi = T. peruvianus = E. pachanoi, unless that is taken as a view that considers T. pachanoi forma peruvianus as de facto T. pachanoi. Friedrich & Rowley transferred T. pachanoi Britton & Rose to Echinopsis as E. pachanoi (Br. & R.) Friedrich & Rowley, and T. peruvianus Britton & Rose to Echinopsis as E. peruviana (Br. & R.) Friedrich & Rowley. I would have expected those two folks to lump them together, but they didn't somehow, which is fine by me

[Guest Mesqualero]

thank you for your informed and much helpful response...

[M S Smith]

Honestly Trichocereus should have never come about as a name at all. The classification of Echinopsis (1837) existed prior to that of Riccobono's Trichocereus, who Britton and Rose later supported. If Riccobono had taken more notice of the flower similarities (how classification of species in the past and present occurs, with newer methods not yet fully acceptable) then he would have been unable to make a new taxon. Why Britton and Rose and Brackeberg followed along I do not know, but I may surmise it had to do simply with different outward morphology rather that flower characteristics. Of course creating new taxa always brings one some minor place in history. The whole process of classification of species had been very political in the past (being a product purely of those with denero in pocket and reputations to uphold) and I personally believe that with Anderson's The Cactus Family quickly becoming the leader we are seeing a much less political (or fame seeking), and more scientific method of plant classification. Chemotaxonomy and DNA analysis may become better methods in the future, but where to make the breaks in the chemistry or DNA sequences that would differentiate taxa will be a difficult thing to establish.

As for E. peruviana and E. pachanoi being the same I would have to disagree. Though they do intergrade that is only due to the ethnological use of E. pachanoi which created importation of E. pachanoi throughout portions of the Andes. At some point they had a common ancestor, they broke off into their own ecological nitches, evolved independently, but not (long) enough so that they couldn't cross once brought together. They originally grew in different locales and then intergraded when E. pachanoi was brought into new territory due to its being found to be enthnopharmacologically useful. Such intergrades are not truly a natural occurance. Without the interferrence of mankind then the process would not occur at the rate it has. Counter to what some may believe, those species which have the ability to cross DO NOT grow naturally in the same environment. If they did then they would never have been able to become distinct species, they would have cancelled each other out to create a single species.

[woof woof woof]

WORD! WORD!

Bless!

Nicely said M. S.!