Morphologic nomenclature

[Robert S Wallace]

In article <3453B7C8.77A8EE34 at mail.utexas.edu>,
Darren Abbey  <darren_a at mail.utexas.edu> wrote:
>Cameron Laird wrote:
>> 
>> What are the "arms" of a saguaro?  Is there a
>> rubric--something like "brachiocarp", perhaps?--
>> for such structures?

	Perhaps you are searcing for a 'synthesized' term.  Brachyclad
(branching segment) may be acceptable (morphologists?), however cactologists
simply refer to these as lateral branches.  These are, of course, stem
segments only, which arise mesotonically from the primary axis.

>> Cameron Laird           http://starbase.neosoft.com/~claird/home.html
>> claird at NeoSoft.com      +1 713 996 8546 FAX
>
>	Last time I was in the Sonoran (or was that Chihuahuan?) desert area
>where the saguaro grow I heard the term saguaro "arms" to mean the
>branches that grow from the main trunk in the older specimens.   I seem
>to recall that the arms don't begin to form until the plants are about
>75 years old, is this correct?

	Seventy-five years is a good approximate estimate, however "arm'
formation in Carnegiea can vary considerably depending upon geographic
location, water availability, and perhaps edaphic conditions.  

HTH,

Rob Wallace

-- 
Robert S. Wallace
Associate Professor of Botany                     "In cerevisia veritas est."
Dept. of Botany - Iowa State Univ.
Ames, Iowa 50011-1020             rwallace at iastate.edu       FAX: 515-294-1337
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