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  Philodendron stenolobum
From: Philip Crabb <treetrustee at yahoo.com> on 2004.08.13 at 19:42:36(11970)
Hi,

I am strictly a beginner aroid hobbyist with questions about "tree" philodendron growth habit.

A plant that is new to me has suffered damage, and I wonder what the prognosis is.

The newest leaves of twin Philodendron stenolobums had been damaged in this way: the petioles of the leaves were present upon arrival but the blades of the leaves were missing, almost as if they were pinched off. In the week since the 7" pot with the two 15" inch tall plants arrived, the terminal petioles turned from green to yellow to brown, so I cut them back to a half an inch long.

My questions are these: Will the plants grow around this damage and simply produce new leaves sometime soon? Or, does Philo. stenolobum, when damaged at the growing tip, stop growing and produce side shoots?

Thank you,

Phil

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From: Philip Crabb <treetrustee at yahoo.com> on 2004.08.15 at 07:47:51(11981)
Hi again,

I mistakenly cut off the spear-shaped sheathes, thinking they were petioles without a leaf blade. One friend said, "Time to get glasses."

All is well, though, because the plants are putting out the new leaves despite the mistaken excisions.

Phil Crabb

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From: "Russ" chammer at cfl.rr.com> on 2005.06.30 at 08:20:25(13081)
Title: RE: [Aroid-l] Philodendron stenolobum and P. bipinnatifidum?

My P. stenolobum has leaves exactly like
those of the large plant featured in last year's Aroid Show. I find it
hard
to believe that the plant that was
called williamsii a few years ago, and was part of the controversy with the
plant now
called stenolobum, could be a variation
of stenolobum. If they are, in fact, all to be called stenolobum, there
will be much
confusion with this species.
Certainly they must be identified under different varietal names to avoid
this.
Russ

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From: a san juan kalim1998 at yahoo.com> on 2005.06.30 at 08:36:11(13082)
"I find it hard to believe that the plant that was
called williamsii a few years ago, and was part of the
controversy with the plant now called stenolobum,
could be a variation of stenolobum."

Why not? All people are the same species, and yet you
can see very much variation in terms of coloration,
height, hair type, etc.

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From: "Julius Boos" ju-bo at msn.com> on 2005.06.30 at 15:46:45(13084)
Reply-To : Discussion of aroids
Sent : Thursday, June 30, 2005 3:20 PM
To : "Discussion of aroids"
Subject : Re: [Aroid-l] Philodendron stenolobum

Dear All,

Here goes---
Before Dr. Goncalves' article in Aroideana Vol. 25, pg.2, there was only ONE
species recognized as P. williamsii by Dr. Simon Mayo, and the plants with
the 'wavy' leaf edge were considered a variety of the P. williamsii complex.
NOW the population from the area of Espirito Santo has been described by
Dr. Goncalves as a different and NEW species (as was suspected by Dr. Mayo),
P. stenolobum (no vars. involved, just TWO valid and different species!!!).
P. stenolobum is very different from the TRUE P. williamsii`s which has,
among differences, a flat leaf blade, and differs in several other VALID
ways from 'true' P. williamsii, plants of which are less common and less
sought after than the newly described and more desirable/'attractive' P.
stenolobum.
Just read Eduardo`s excellent article in Aroideana Vol 25, all will become
clear!!

Good Growing,

Julius

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From: Neil Crafter golfstra at senet.com.au> on 2005.06.30 at 17:19:49(13085)
Russ and Eduardo
I have both these plants - the 'new' P stenolobum and the 'old' P. williamsii. Like you Russ, I think that just by looking at them that they are different species. Old williamsii's leaves are longer, narrower and much stiffer and I suspect the petioles are typically longer too. Eduardo, you are saying that the plant considered by most people to be P. williamsii is not the true williamsii as this has a broader leaf like speciosum. Then what is the 'old' P. williamsii then? Is it a sub-species of stenolobum or something without a name that needs to be described? Look forward to shedding more light on this.
cheers
Neil

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From: "Russ" chammer at cfl.rr.com> on 2005.07.01 at 07:51:40(13086)
Yes, and for identification purposes those physical features and origins in
general are broken down into Caucasian, Hispanic, etc, etc. Also, science
demands that these horticultural differences are identified and split into
identifiable physical characteristics, and named. In the present state of
affairs, if I say I have a stenolobum, no one still knows exactly which
philodendron I have, and this situation is just too ambiguous.
Russ

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From: "Russ" chammer at cfl.rr.com> on 2005.07.01 at 08:14:08(13087)
The leaves on my 'stenolobum' are nowhere
near as ruffled as the one in last year's Aroid show, or the 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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From: a san juan kalim1998 at yahoo.com> on 2005.07.01 at 08:23:08(13088)
"Is it a sub-species of stenolobum or something
without a name that needs to be described? Look
forward to shedding more light on this. cheers"

Good point, and worth a look by Eduardo, although
again depending on just subtle leaf shape might not be
enough, especially if Eduardo is seeing a continuum of
leaf shapes for this 'old' P. williamsii/P. stenolobum
in the local area. I'll take more pics of the 'old' P.
williamsii/P. stenolobum - perhaps this 'mystery' can
be solved.

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From: a san juan kalim1998 at yahoo.com> on 2005.07.01 at 14:16:59(13089)
Agreed on this. The discussion was on whether the
plant in question is P. stenolobum, not whether there
should be some way of differentiating (due to innate
differences in leaf form) various forms of this plant
in cultivation. In the wild, it may be that the P.
stenolobum population shows a continuous range in form
from the 'old williamsii' to the 'new stenolobum'....

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From: a san juan kalim1998 at yahoo.com> on 2005.07.01 at 14:21:32(13090)
Could you give numbers for the ratios? I'm curious,
and glad this conversation came up.

--- Russ wrote:

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From: a san juan kalim1998 at yahoo.com> on 2005.07.01 at 19:25:24(13092)
closer pic of one of the leaves of this young plant:
http://www.blueboard.com/pahatan/gambar/images/2005_7_1_asj_p_stenolobum_1.jpg

there are forms of this species that do seem to have
narrower and longer posterior lobes, as well as
narrower leaves:

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From: "Julius Boos" ju-bo at msn.com> on 2005.07.02 at 04:02:26(13095)
Reply-To : Discussion of aroids
Sent : Friday, July 1, 2005 9:21 PM
To : Discussion of aroids
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.

Julius

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From: a san juan kalim1998 at yahoo.com> on 2005.07.02 at 12:40:32(13098)
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....

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From: a san juan kalim1998 at yahoo.com> on 2005.07.02 at 13:24:59(13100)
"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...."

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From: "Julius Boos" ju-bo at msn.com> on 2005.07.02 at 14:18:54(13101)

Sent : Saturday, July 2, 2005 7:40 PM
To : Discussion of aroids
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!

Julius

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From: "Michael Pascall" mickpascall at hotmail.com> on 2005.07.02 at 17:40:15(13102)
As Julius said 'Just read Eduardo`s excellent article in Aroideana Vol 25,
all will become clear!!
all of this discussion would not be needed , seems many members of this list
still are not members !!

Michael Pascall,

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From: Neil Crafter golfstra at senet.com.au> on 2005.07.02 at 18:17:56(13104)
Julius
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. 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 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.

cheers Neil

Neil Crafter

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From: a san juan kalim1998 at yahoo.com> on 2005.07.02 at 19:21:11(13108)
"Leaf shape or leaf lobe shape/length play a VERY
minor
role in the determination of species."

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From: "Russ" chammer at cfl.rr.com> on 2005.07.02 at 21:39:04(13109)
Understood regarding the many forms of P. stenolobum. Obviously, those
examples in submitted photos here whether smooth or ruffled edged, are
stenolobum. While Eduardo's piece in Aroideana 25 was
enlightening, the questions presented here were not clearly answered to the
layman. It is a scientific presentation, hence, the postings.

I'll try to find the confusing philo I'm referencing and take some pictures
to submit. While it was sold by
IAS members at Fla west coast botanic gardens as 'williamsii', it is
certainly not the rare williamsii, and I'm doubting it's one of the
stenolobum group. The leaf is triangular but lobes not narrow. It has an
obvious lack of dark green color that is confirmed by Eduardo as typical of
stenolobum, and lacks the stiff, leathery consistency I observe on my own
stenolobum. Are these disqualifying factors without going into gynoecium,
styles, ovaries, etc?

Russ

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From: "Michael Pascall" mickpascall at hotmail.com> on 2005.07.03 at 01:20:03(13112)
With the many seedlings of P. stenolobum being grown here , I have noticed
an obvious difference in the appearance of the foliage , depending on where
its grown , absoloute all day full sun , will give a much narrower ruffled
leaf , and in a protected position the leaf is more soft and much broader .

Michael Pascall,

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From: "Julius Boos" ju-bo at msn.com> on 2005.07.03 at 08:45:44(13114)
Reply-To : Discussion of aroids
Sent : Sunday, July 3, 2005 1:17 AM
To : Discussion of aroids
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!!
Julius

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From: HUDSONSBIRDS at webtv.net on 2005.07.03 at 09:48:34(13115)
Is the Stenolobum "knotted" yet?

_______________________________________________
Aroid-l mailing list

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From: a san juan kalim1998 at yahoo.com> on 2005.07.03 at 10:40:04(13116)
Very interesting, which again points to the
possibility that using leaf shape and leaf edges in
this case is not the way to go in determining species,
since the characteristic seems very dependent on
external environmental conditions.

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From: "Eduardo Goncalves" edggon at hotmail.com> on 2005.07.05 at 04:22:21(13122)
Please,

Add somewhere a picture of this "old" P. williamsii and post a link
in this list. All "P. williamsii" I could see in USA or in North America are
P. stenolobum. Maybe you have a different plant. There are a few hybrids
involving P. stenolobum and other species, so maybe you are talking about
oune of this.

Very best wishes,

Eduardo.

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From: "Eduardo Goncalves" edggon at hotmail.com> on 2005.07.05 at 04:35:15(13123)
Dear all,

I simply echo Julus?post. Whatever you want to call all this variations
of narrow-lobed (or, in latin, stenolobum) philodendron, THEY ARE NOT P.
WILLIAMSII. Unfortunately, I don?t have a picture here of the real P.
williamsii to post. Anyhow, all material I have seen are forms of P.
stenolobum and since I do not believe in varietal names (they are almost
invariably superfluous), I keep calling then P. stenolobum. If you sell
them, you can add a name on this, like P. stenolobum "Ruffled-edge" or P.
stenolobum "Short ears", but I can?t see any need of a binomial changing.

Very best wishes,

Eduardo.

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From: a san juan kalim1998 at yahoo.com> on 2005.07.06 at 05:15:24(13139)
Well, here's an example of how people can exploit the
confusion regarding P. stenolobum:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category%463&item983469256&rd=1

That form is very attractive though.

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From: "Eduardo Goncalves" edggon at hotmail.com> on 2005.07.08 at 06:42:43(13154)
That makes me laugh... (or cry)

The guy said that P. stenolobum is very rare and P. williamsii
very common. And that material is from Amazonia!!!! Well, for those that
don?t know, the real P. williamsii is from the coastal forests in eastern
Brazil and P. stenolobum is from dryier areas at least 500 km to the
south... I have just seen P. williamsii in the field (last week) but it was
too high in the canopy to make a good picture.

Very best wishes,

Eduardo.

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From: a san juan kalim1998 at yahoo.com> on 2005.07.10 at 22:29:34(13167)
well, some other people are starting to use the new
name 'P. stenolobum' ;-)

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category%463&itemw00041508&rd=1

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From: "Denis Rotolante" denis at skg.com> on 2005.07.12 at 11:19:33(13171)
ONE OF OUR PHILO. STENOLOBUM DEVELOPED AN INFRUCTESCENCE AND BILL
PLANTED OUT THE SEEDS IN TRAYS.
WE NOW HAVE 1800 LITTLE STENOLOBUM SEEDLINGS IN 98 COUNT TRAYS. IF ANY
OF THE OTHER COMMERCIAL GROWERS OUT THERE IN AROID L WOULD LIKE SOME, I
CAN SELL YOU A FEW AS I DID NOT INTEND TO PLANT THAT MANY... GIVE ME A
MONTH OR TWO TO GET THEM TO A BIGGER SIZE.

DENIS ROTOLANTE

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From: "Russ" chammer at cfl.rr.com> on 2005.07.14 at 07:53:28(13177)
Just out of curiosity, Denis, would those seedlings be hybrids or
self-pollinated?

By the way, you know my brother Roger Hammer who lives in Homestead and is a
naturalist with Dade
county parks system.

Russ

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