More on S. rosea

From: Aaron M. Ellison (aellison@mtholyoke.edu)
Date: Fri Feb 25 2000 - 05:38:40 PST


Date: Fri, 25 Feb 2000 08:38:40 -0500 (EST)
From: "Aaron M. Ellison" <aellison@mtholyoke.edu>
To: cp@opus.hpl.hp.com
Message-Id: <aabcdefg550$foo@default>
Subject: More on S. rosea

In response to Barry's comments about S. rosea, I add the following.

A recent paper by Godt & Hamrick (M. J. W. Godt and J. L. Hamrick. Genetic
divergence among infraspecific taxa of Sarracenia purpurea. Systematic
Botany 23:427-438, 1998.) looked at genetic differences among the two
subspecies of S. purpurea and the different varieties of subspecies venosa
(var. burkii, var. montana, var. venosa. Their results show that var.
burkii is clearly very different not only from S. purpurea ssp. purpurea,
but also from the other two varieties of ssp. venosa. In fact, their
results show that the venosa var. montana and venosa var. venosa are more
closely related to ssp. purpurea than any of them are to var. burkii.

My recent research on seed characteristics and germination and dormancy
within S. purpurea (just submitted this week to American Journal of
Botany) come to the same conclusion about the different subspecies and
varieties of S. purpurea.

If one were to combine the genetic analysis of Godt & Hamrick with
morphological analysis of Naczi et al, and with my work on germination
biology of this species, the most reasonable conclusion is that there
would be two species: S. purpurea and S. rosea, and that what we consider
subspecies (ssp. purpurea and ssp. venosa) and varieties within ssp.
venosa (var. venosa and var. montana) are really just normal variability
within S. purpurea. Perhaps this is a good compromise between lumping and
splitting...except for S. rosea (= S. purpurea ssp. venosa var. burkii),
all the rest should be S. purpurea, with no further divisions into ssp. or
varities (although there are conservation issues associated with S. p.
ssp. venosa var. montana, as discussed by Godt & Hamrick).

Aaron Ellison



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