Thomas G. Lammers
lammers at uwosh.edu
Mon Feb 22 14:39:31 CST 2010
At 02:06 PM 2/22/2010, Kenneth Kinman wrote:
>But weren't the paleodicots always thought of as dicots primarily
>because of their dicotyledonous seedlings?
Yes. But in many of the other characters traditionally used to distinguish
the two, they fail. There is a great deal of trimery in flowers of these
families (a supposed monocot character), despite "4's or 5's or multiples
thereof" being the dicot standard. Some like Piperaceae have scattered
vascular bundles when the stem is viewed in cross-section, a supposedly
I agree that a fundamental dichotomy is a nice thing to have. But about 5%
of our species belong to lineages whose origin pre-date that event.
I just think its one of those places where we traditionalists can concede
to a cladistic view without really causing ourselves any problem.
If we were to depict phylogeny in a Besseyan fashion instead of a Hennigian
one, I could see a little blob at base (the basal lineages or "monosulcate
dicots") with two large blobs arising, the monocots and dicots (triaperurates).
Thomas G. Lammers, Ph.D.
Curator of the Neil A. Harriman Herbarium (OSH)
Department of Biology and Microbiology
800 Algoma Blvd.
University of Wisconsin Oshkosh
Oshkosh, Wisconsin 54901-8640 USA
e-mail: lammers at uwosh.edu
Plant systematics; classification, nomenclature, evolution, and
biogeography of the Campanulaceae s. lat.
"Today's mighty oak is yesterday's nut that stood his ground."
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