Stephen P. Rae
srae at MUSCI.COM
Wed May 14 22:29:33 CDT 1997
At the risk of sounding critical, is it possible that the large number of
species in this genus may be an anomaly due to erection by taxonomists?
What you describe is a very large number of closely related taxa in a small
area. We in California have closely related taxa in close proximity, more
so than in most other areas of North America. But, your report exceeds our
Is there any possiblity that the group needs a revision (or, at least, a
treatment to determine if synonmy occus)?
As for competition, I can think of Polygonum, Lupinus, Ceanotus, and
Arctostaphylos in certain parts of California. We can find five or six
species of each within 100 sq m in many locations. Where particular and
restricted edaphic conditions occur, even more species may be found nearby,
but it is not common, But, we can't challenge the 650 total.
I will look forward to the responses generated by your challenge.
At 12:48 PM 5/14/97 SAST-2, Ted Oliver wrote:
>If there were entries in the Guiness Book of Records for
>biodiversity in the plant kingdom what would the candidates be?
>My research is on the genus Erica which I reckon is a very good
>candidate from the following figures:-
>On a mountain slope near the coast SE of Cape Town I noted 5 species
>growing within 1 square metre (woody shrublets to 300 mm high) and :
>on the flats nearby 11 species in about 1000 sq m, 9 of them
>flowering and all very distinct species not closely related with
>pollination by either bees, birds or wind.
>The centre of biodiversity of the genus lies just to the north of
>the above area and so far we estimate that 200 spp occur in a
>mountain range of approx 30x10 km=300 sq km.
>The genus has presently 650 spp in the Cape Floral Region (approx 90
>000 sq km) with approx 95% endemism.
>Has anyone got comparable figures for other genera in other parts of
>the world? Is this a possible record for vascular plants?
>E.G.H. `Ted' OLIVER (Mr)
>National Botanical Institute, Kirstenbosch
>P Bag X7, Claremont, 7735 SOUTH AFRICA
>Tel: +27 21 7621166 Fax: +27 21 761 4151
>olivert at nbict.nbi.ac.za
Stephen P. Rae
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