Morphologic nomenclature

Robert S Wallace rwallace at
Mon Oct 27 17:31:59 EST 1997

In article <3453B7C8.77A8EE34 at>,
Darren Abbey  <darren_a at> 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 
>> claird at      +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.  


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       FAX: 515-294-1337

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