Sassafra Leaf Morph distribution

Martha K Jensen mkjensen at
Thu Dec 9 15:10:24 EST 1993

>In article <kwestin1-071293164330 at> kwestin1
>>Two undergrads at Swarthmore College are looking at the distribution of
>>three leaf morph shapes over a range of trees, species Sassafras albidum.
>>We've found a strong correlation between percent unlobed leaves and age -
>>the older the entire tree (not just the branch), the more unlobed leaves it
>>has.  A literature search has turned up very little and we're brainstormed
>>out.  Any ideas, however wild, entertained!  Can _you_ think of a reason
>>for the correlation?  Responses, questions sent to
>>kwestin1 at   Many thanks!
>I can't speak to this specific problem, but there are many examples (some
>published, even more observational or anecdotal) of developmental trends
>in woody plants related to maturation.  One simple explanation might be
>that leaves w/o lobes tend to be more frequent as trees mature
>(which you've
>already observed).  Age and maturation state are not perfectly correlated,
>however.  Other examples of maturation-related phenomena include the
>relative abundance of male vs female reproductive structures (on
>monoecious species such as conifers), rooting ability, etc.  You might
>check the literature on woody plants using search terms such as
>maturation, juvenility, rejuvenation.  Two authors who come to mind are
>Michael Greenwood and William J. Libby.
>Good luck!
>David Harry                     

Seeing this article reminded me of a passage I noticed recently in a
botany text, having to do with different leaf morphology in juvenile
and adult plants.  The plants that they specifically mentioned were
engligh ivy (Hedera helix?) and eucalyptus.  I vaguely remember that the
different leaf shapes had something to do with hormone levels.  If
you are interested, I can try to find the passage again.  I think
it was discussed in "Biology of Plants" by Raven, Evert and Eichhorn ??

Good Luck!


mkjensen at


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