You may want to reconsider defining all plants with perennial
above-ground stems as "woody". There are quite a number of species with
perennial, -herbaceous-, above-ground stems. Some examples: Tillandsia
usneoides, Dendrobium chrysanthum, Phlegmariurus dichotomus,
Diphasiastrum digitatum, Peperomia obtusifolia, Anthurium scandens,
Bouteloua eriopoda, etc. Others seem to fall into grey areas, with more
or less creeping stems that require some arbitrary cutoff regarding what
qualifies as "above-ground", erect stems that are fairly robust but
would not normally be considered "woody", short & inconspicuous erect
stems generally hidden in rosettes, etc., e.g.: Philodendron
pinnatifidum, Davallia fejeensis, Agave parryi, Costus barbatus,
Selaginella kraussiana, etc. Some of the affected groups (especially
epiphytic orchids) are quite speciose, so this is not a trivial problem.
My offhand guess would be that around 10-15% of all vascular plant
species would either be clearly mischaracterized as woody or would fall
into various subjective grey areas. This may be as large as or larger
than percentage of vascular plant species that in fact -are- woody.
Regards,
Patrick Alexander
On 6/5/12 12:13 PM, Matt Pennell wrote:
This is perhaps an unconventional use of the r-sig-phylo mailing list. Rather
than asking for advice
on how to do an analysis, I am enlisting the expertise of the community to try
and actually help do
the analysis. If you have a few seconds, I would really appreciate it if you
could help us out.
Woody versus herbaceous is one of the major axes of life history variation in
plants. We sought to find
the answer to the seemingly simple question: what percentage of plant species
in the world are
woody? We asked a small group of botanists this question and got an
extraordinarily wide variety of
answers. In addition to tallying up the species numbers, we (here "we" refers
to myself along with Rich
Fitzjohn, Amy Zanne, Will Cornwell and others involved with our NESCent working
group: "Tempo and
Mode of Plant Trait Evolution") thought it would be interesting to survey
biology-types to see if a
general consensus answer exists. Please take a couple of seconds to fill out
our questionnaire.
Thanks! Answer coming out soon in a journal near you.
Questionnaire is here: https://docs.google.com/spreadsheet/viewform?
formkey=dDBDOXpUeGpXSWJESmV0TjNrWHFEMUE6MQ
Thanks a lot,
Matt, Rich, Will and Amy
