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  P. williamsii/P. stenolobum-a resoloution
From: "Julius Boos" ju-bo at msn.com> on 2005.07.10 at 07:40:09(13165)
Dear Folks,

Some of the final correspondence on this tricky subject was carried on
off the aroid-L; this was caused mainly by the difficulty of posting pics.,
etc . I thought I`d pass on what seems to be a final resoloution on the
determination of what these two species really are, and what was the final
outcome concerning a WONDERFUL old illus. mentioned by Neil Crafter, who
lives and grows aroids in
Australia . This illus., plus great information supplied by Dr. Goncalves
in Brazil, were the final 'clinchers' in the discussion. A few more
snippets of info. came to light which I will also mention here, and with
luck we will soon have an actual photo of a living plant of TRUE P.
williamsii somewhere on aroid-L!!!! Now THAT is something!
OK, here goes. P. williamsii, it turns out, is a GOOD species described
by J. B. Hooker. The description, together with a great hand-drawn
illustration, was published in a Botanical Magazine # 5899 in 1891. The
type specimen/plant (which ultimately was grown at Kew Gardens in England),
was collected in Bahia, Coastal Brazil, and was sent to J. B. Hooker in
England by a Mr. Williams, and so was named in Mr. Williams` honor. It
differs completely from Dr. Goncalves` P. stenolobum, which occurs only in
Cen. Brazil further to the South. ( see Eduardo`s note on this subject
recently posted on aroid-l ).
The BIG differences between these two species, which can be seen and
appreciated by us amatures, are the differences/ratios in measurements of
the anterior lobe the leaf, the differences in the shape of their
respective gynociums/ovaries, and the differences in the number of
locules/chambers in their ovaries. All of these differences can be easily
observed by comparing the two illustrations of these two plants, one by Dr.
Goncalves in Aroidiana Vol. 25 of 2002 (P. stenolobum), and the other in the
illustration by J. B. Hooker dating back to 1891, which Neil so very kindly
posted to me. Perhaps Neil could post this wonderful illus. on to a site
on one of our aroid pages, or give a link to a web page that he might create
on which interested parties can view this work of art?? The drawing of
the ovary in cross section is a little dim in the Hooker illustration, but
Neil very kindly gave me a count of the chambers taken off of his copy, and
it corresponds perfectly with the chart given by Dr. Goncalves on pg. 6 of
Aroideana Vol 25, for P. williamsii the count given is "11-12 locules", the
illus. by Hooker shows 12 locules! This is in contrast to only 7 - 8
locules in P. stenolobum illustrated by Dr. Goncalves on pg. 7.
Another bit of incredible good news to us fans of the Meconostigma group of
Philodendrons, is that an actual plant of P. williamsii has turned up here
in Florida, just a week or so ago! It is only one mature plant of an
actual collection made MANY years ago in Bahia, Coastal Brazil, so I am
working on getting both the collection data and a photo up SOMEWHERE so that
we can all see an actual speciman of TRUE P. williamsii.
So---thanks to the efforts of several good aroid-nuts, I hope most questions
regarding doubts on what is what with these two wonderful species of
Philodendrons have ALL been answered!

Good Growing,

Julius

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