pcplantdb

[Richard Morris <webmaster@pfaf.org>]

John Schinnerer wrote:

> Aloha,
>
>
> > ...So it seems that treeness does not really tie well with the typical
> > plant systematics.
>
>
> Of course, because "typical plant systematics" are but one of an infinite
> number of possible ways of classifying plants, all of which are arbitrary

You could say that the botanical plant systematics are the
only non arbitary way of classifying plants.

There is a real relationship between members of a clade (plants which 
share a common ancestor, eg most families and genuses form clades). A 
relationship in nature not a man made relationship. This relationship 
ties well with differences in the dna of plants and with some physical 
characteristics of the plants (shape of flowers, arangement of overaries 
etc.)

The underlying plant family tree is not arbitary, what is arbitary are 
the particular names given to different plants.

A very interesting in new scientist this week. A group of rogue 
taxonomists want to get rid of all higher order groupings, above 
species. Nature does not really have a concept of a family or genus, it 
justs has clades. There are some grouping such as the genus Potentilla 
which do not form natural evolutionary grouping. They want to repace 
these grouping with a PhyloCode which indicates a particular clade.

Sometimes even the concept of a species fails. In blackberries (UK 
common name) Rubus fruticosus, the species consists of a large number of 
micro species and it could be said that each plant form its own species. 
This is because blackberries reproduce by Apomictic where seeds form 
without sexual fusion.

Anyway this is all rather off the point, family genus and species
serve our needs very well and we should stear clear of getting too 
botanical.

        ttfn

                Rich

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