Peter Stevens peter.stevens at MOBOT.ORG
Sun Oct 5 18:01:04 CDT 2003

At 10:58 AM -0400 10/3/03, John Grehan wrote:
>I asked one
>molecular geneticist at the Pennsylvania State University, for example,
>about how the Podostemaceae fitted into their picture, particularly with
>respect to the lack of structural homology with the absence of a shoot/root
>separation in development, the lack of roots, and problems in the homology
>of floral structure the response was one of complete indifference.

Oh dear, what an unholy mess - essentialiasm, molecules, cladistics, phylocode.

I must say that although molecules are indeed leading to the current
revisions in higher-level relationships, it is heartening to see how
often (but not always) morphology also makes eminent sense.  When
molecules suggested Platyspermation (previously Rutaceae) was
Alseuosmiaceae, a brief trip to the herbarium showed it had the
unisreiate hairs that may be a synapomorphy of the family, a similar
corolla, etc.  And I was looking at "Tremandraceae" yesterday around
Melbourne, and there were the pendulous flowers and porose anthers
common in other Elaeocarps - not to mention the less obvious
similarities that floral developmental studies have recently
emphasized.  And Podostems and Clusiaceae (well, perhaps
Hypericaceae)? - ovules, perhaps secretions and xanthones, etc.

Life isn't easy, but when knees stop jerking, it is fun.

Peter S.

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