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Re: [Aroid-l] Philodendron stenolobum

  • Subject: Re: [Aroid-l] Philodendron stenolobum
  • From: "Julius Boos" ju-bo@msn.com
  • Date: Sun, 03 Jul 2005 15:45:44 +0000

From : 	Neil Crafter <golfstra@senet.com.au>
Reply-To : Discussion of aroids <aroid-l@gizmoworks.com>
Sent : Sunday, July 3, 2005 1:17 AM
To : Discussion of aroids <aroid-l@gizmoworks.com>
Subject : Re: [Aroid-l] Philodendron stenolobum

Hello Neil!

[To 'a San Juan '---Your photo which you so kindly sent of the stem/rhizome of P. stenolobum seems a PERFECT match for Dr. Goncalves` B+W photo of the stem of P. stenolobum on Pg. 9, Fig. 8, of his article describing this species in 'Aroideana Volume 25'.]

Good to hear your voice, mate! I`m so deep into this discussion (which I really should back out of at this stage, and leave it to Dr. Goncalves and Dr. Croat!!!) but your point about the old, 1871 Hooker illustration has 'tickled' my interest-bone, as the part that I love best about taxonomy is all the detective work on investigating the history of a plant! (remind me to tell you about my investigations 'back when' on Dracontium foecundum Hook. and D. asperum K. Koch, fun fun fun!! By the way!!!--- Dr. Zhu`s revision of the genus Dracontium has been published, it is in 'Annals of the Missouri Bot. Garden 2004, Vol. 91, Number 4'!!!) I`ll reply below each of your paragraphs (below) as is my want. HOPEFULLY Dr. Goncalves will ''jump into'' the discussion with both feet, as he was the person who did the actual research to decide that P. stenolobum was a new s pecies, different to P. williamsii, and what P. williamsii really was/is!!
Very clear and message received. I guess it's hard for us amateurs who do not have access to herbarium material, microscopes, gynoeciums and locules (let alone flowering material - my old P. 'williamsii' is at least 20 years old and has never flowered) to try and identify the plants in our collections. <<

I am surprised that your plant has never bloomed, from what I know it blooms on a regular basis here in Florida, and hybrids have been created with it and P. bipinnatifidum!. It is unfortunate that most species MUST depend on examination of the sexual parts, color of dried herbarium specimens, etc., but I don`t make the rules! I wait till someone tries to do the revision of Urospatha, I feel that it may yet involve the smells of the different species' blooms!

For myself, the tendency to rely on what I can observe of the plants is perhaps overwhelming at times, especially when the division between species may come down to microscopic structural differences in their flowers. Having further examined my old 'williamsii' and new stenolobum, I am struck by the similarities in petiole cross section and trunk appearance, with the only apparent 'difference' being the leaf blade shape and its stiffness.<<
This makes my point exactly, were we in the wilds of Brazil, I would warrant that we would see populations, ALL being P. stenolobum, but differing one from the other in leaf shape, texture, etc. BUT---as collectors and human beings, we`d choose only the 'more beautiful' plants from a population which we`d collect, NOT the more drab, less 'shapely' specimens!! This happened to Lynn, Mary, my brother Hans and myself when we visited Joep Moonen in Fr. Guyana ( a trip I HIGHLY recomend to plant people!!), there was a species of climbing/rambling Philo. there that was exceedingly common EVERYWHERE, even around the capital city, quite an attractive plant, and we collected a few as just samples. BUT---then Joep so very kindly took us to visit his secret and 'private reserve' population of this SAME species, a VERY small, restricted population, all growing in a tiny valley, all growing against the trunks of stunted trees. MAN! WOW!!! HELL!!!! Extra- long, extra narrow leaves, shorter, horizontal and BRIGHT orange petioles and leaf veins, very compact growth habit!!! We were allowed, under Joep`s expert eyes and guidance, to collect only a VERY limited number of tip-cuttings, thus preserving the population, and these cuttings and their divisions are treasured by their owners, and when rarely available at auction, go for big $$ here in Miami!!! Man GENERALLY selects the most attractive individuals of several populations of either plants OR animals to suite his personal tastes!!

This problem with P 'williamsii' would appear to go a long way back. I have a copy in my files of a beautiful coloured drawing and the first description of P. williamsii in one of the early botanical publications, the Botanical Magazine (5899) - the plant looks like stenolobum more than the longer bladed variation. The author had the initials of JBH (Hooker?) and he described the plant as being sent to Kew by Mr Williams of Bahia, giving it the name of Philodendron williamsii. The paper has a date of May 1871. A question for Eduardo. Is this the true P.williamsii you refer to which is only known from some herbarium material? or was this plant misnamed from the start.<<
NOW you have tickled my DEEP interest! We MUST wait for Eduardo`s reply and determine IF this old illustration AND DESCRIPTION entered into his research and decisions on P. stenolobum and P. williamsii!! I hope Dr. Goncalves manages to reply soon! Any chance of scanning this illus. to the list??? Look out for the copyright BS.

cheers Neil<<
Cheers, Best Wishes, and Good Growing!

WPB, Florida

Neil Crafter
Philodendron enthusiast
Adelaide, Australia<<

On 03/07/2005, at 6:48 AM, Julius Boos wrote:

Sent : Saturday, July 2, 2005 7:40 PM
To : Discussion of aroids <aroid-l@gizmoworks.com>
Subject : Re: [Aroid-l] Philodendron stenolobum

Dear All,

I still do not think you guys understand what is being said--- ALL these photos that are being discussed, plants with the longer narrower ruffled leaf blades, the long FLAT leaf blades, the slightly shorter leaf blades with or without ruffles, slightly longer lobes, slightly shorter lobes, ALL are variations from different collections throughout the range of P. stenolobum, a range FAR distant from where TRUE P. williamsii occurs. NONE of the plants being seen or discussed are a different species OR P. williamsii. Leaf shape or leaf lobe shape/length play a VERY minor role in the determination of species. ALL the plants pictured and being discussed should or will have barrel-shaped gynociums (not flask-shaped as in P. williamsii), ALL will have only 7-8 locules (not 11-12 as is found in P. williamsii) and all will fall within the anterior leaf blade ratio of P. stenolobum, so ALL will be classified as P. stenolobum, NOT another species, and NOT P. williamsii. If it rings your bells, or makes them more expensive/easier to sell, knock yourself out and give them 'cultivar' or 'var.' names, but this only confuses the issue further.
Read and understand Dr. Goncalves recent postings.

Good Growing!


Very nicely put!

As you say, some cultivated samples may tend to be
those that are "extreme" samples from the wild, and
thus are not truly representative of the "average"
look of the species (that is, the wild population may
form a continuum of plant forms).

The pic of one of the leaves of that small plant
called "P. williamsii" shows short lobes but with
edges that are ruffled (and some of newer leaves just
coming out are starting to get even more 'wavy'):

http://www.blueboard.com/pahatan/gambar/images/ 2005_7_1_asj_p_stenolobum_1.jpg

I looked at pics of P. stenolobum from that paper and
they look similar in lobe shape to the short form - so
maybe it's the "long lobe" form that needs a new name
- LOL....

But, honestly, i do like the ones with longer, thinner
lobes though ;-)

--- Julius Boos <ju-bo@msn.com> wrote:

From : a san juan <kalim1998@yahoo.com>
Reply-To : Discussion of aroids
Sent : Friday, July 1, 2005 9:21 PM
To : Discussion of aroids <aroid-l@gizmoworks.com>
Subject : Re: [Aroid-l] Philodendron stenolobum

Dear Friends,

Eduardo has informed us of exactly what the case is
w/ these two very different and 'good' species (see his letter of
30th, 8.18 pm, addressed to 'Tom" (Dr. Croat), but allow me one more explanation
on what might have and may still be causing some confusion.

[By the way, the leaf ratios asked for on these two
species are---"Anterior division (ratio length/width)
P. williamsii--1 - 1.5.
P. stenolobum 2.1 - 3.3.
(these are copied from Dr. Gonclaves' paper)
Other critical differences that separate these two
species documented by Dr. Goncalves in his paper are--The gynoceum (immature
fruit) in P. stenolobum is flask-shaped, while that of P. williamsii is
barrel shaped. The ovary of P. stenolobum has 11-12 locules (chambers) while
that of P. williamsii has only 7-8.]

Before Dr. Goncalves published his paper, when
word got out that the plant that we all had been refering to as P. williamsii
was going to be described as a new/good species, several collectors/growers
then assumed that only the plants with the ruffled leaf edges were this new
species ( P. stenolobum), and the plants with the not-so-long anterior lobes
and flat leaf blades must still be P. williamsii--- we were wrong! The TRUE
P. williamsii is a completely different species, seemingly not in
cultivation, rare in herbarium collections, and very different looking to
either one of the vars. of the now-new P. stenolobum, and grows FAR away
from all the different populations of the new P. stenolobum. (see
Eduardo`s recent letter on this).
So--the plants that have a very long leaf, both the
ruffled and the unruffled, ALL are TRUE P. stenolobum. Man ALWAYS
gravitates to collecting from wild populations what he views as the most
attractive or even odd members of a broard variety of either plants or
animals, it happens all the time with collectors, but true scientists collect
'down the middle', a representitive sample that illustrates the extremes
of a species. This obviously pertains to the plants under discussion,
all seen are P. stenolobum.

WPB, Florida

Could you give numbers for the ratios? I'm
and glad this conversation came up.<<

--- Russ <chammer@cfl.rr.com> wrote:

The leaves on my 'stenolobum' are nowhere near as
ruffled as the one in last year's Aroid show, or
2 pictures I found
of P. 'williamsii' in my Exotica.  But they seem to
be the same in narrow lobe width and proportions.
So, these are obviously >both stenolobum with a
variation in the leaf edge.  BUT, these are not the
two opposing plants I have in mind as questionable.
The 'old williamsii' >that I'm referencing has much
shorter, and wider lobes, and leaves are not as
thick or stiff.  They truly do not look like the
same species.  Russ>


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