Echinopsis

ECHINOPSIS

Cactus taxonomy is in a state of flux. It has been from the start. The genus Cactus, established in 1759 by Linnaeus had to be abandoned very early on it was so fluxed.
In modern times molecular genetics has started to play a significant role in taxonomy and it is revealing relationships that had previously been discounted. In same ways this is unfortunate for those of us who hate change, however it does mean that taxonomic questions can be approached with less trepidation. There is less rib counting, less areole investigation and fewer spines to extract. There is altogether less poking of an actual cactus. We are also given a short respite from the desperate linguistic race to find ever more obscure technical terms to describe a round green blob with reproducible precision.
It isn't all bad.
Echinopsis could be seen as one of the beneficiaries of the new approach, the genus has gobbled up all sorts of its relatives and although this creates some conceptual confusion, we will all get over it eventually. We have all become accustomed to Echinopsis as small, rounded cacti with very large, short lived flowers and there are a multitude of hybrids and horticultural selections that emphasise those characteristics. New additions to the genus will require us to change our expectations. One early addition was Lobivia. The whole genus has been subsumed into Echinopsis and it will result in some unfamiliar names appearing accompanied by dirty looks from the old folk. Chamaecereus silvestrii has also bitten the taxonomic bullet and jumped into Echinopsis.
The consequence is that all of the x Chamaelobivia hybrids (and there are hundreds of them) with their distinctive offsetting form and smaller flowers will now be listed as Echinopsis hybrids. They are so distinctive that for now I am going to refer to them as the Chamaelobivia Group and perhaps that will help to ease a difficult transition.

(I haven't yet reconciled the new nomenclatural combinations so some of these names are tentative and will be confirmed at a later date).