Haworthia species list
Bruce Bayer, Feb 24th 2009
(superceding that in Alsterworthia 2006)
Bruce Bayer at his greenhouse
Photo by David Martin
This new list suggests a new order for Haworthia.
Haworthia species list can be viewed at this link.
Note that the typical variety has been dispensed with.
Instead notable variants of unspecified rank are listed and it is suggested that many of the recent new species names – and in fact some of the older historical names can be re-instituted at will within what I consider to be this close-to-natural order. Thus there is no pretension to a full understanding of relationships beyond some primary order.
Formal botanical names are group names and it may be necessary to specify when a name is essentially a single clone eg. H. retusa ‘geraldii’ (cl). Author names are probably necessary to trace origins of names and also to attach some degree of ‘authority’ and ‘authenticity’, as clearly there is considerable confusion about what constitutes an element of botanical significance as opposed to collector and trade interest and value.
This system allows for populations to be recognized eg H. mutica ‘MBB7801’ or H. mutica ‘Buffeljags’. Possibly there should be a category for populations that appear to be of hybrid origin eg H.X retusaXmirabilis (for say MBB7234 Die Plotte, Heidelberg).
3 comments:
I don't get why they took away the "Turgida" species and put it within the "Retusa." Turgida v. Suberecta doesn't look much like a Retusa at all.
If you asked taxonomists to describe the homo sapien species, they probly would divide us into several. I thought the basic definition of a species was that sexual reproduction between them produced viable off-spring.
There is no universal agreement in biology as to what constitutes a species. That's not to say there is disagreement as to the existence of "species" as a concept, but it is an artifical grouping for purposes of classification, so there are many schools of thought on what makes a species.
The whole "producing viable offspring" is a VERY old-school, outdated concept, but since it's the one that we all hear in grade school, it tends to stick in the mind. Using that as a yardstick, however, would reduce the bromeliad and orchid families to a small number of species, maybe even single digits for orchids, so that's definitely NOT a workable standard, especially for plants. Even among animals, you find many species that live side by side but DON'T interbreed, even though they could, successfully (in fish, platys and swordtails are the classic example). In plants, the structure of the reproductive organs takes precedence, so that's why a "species" like H. magnifica can contain so many widely different forms.
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