Date: 10/20/2000 9:19:04 AM Eastern Daylight Time
Sender: aroid-l@mobot.org
Reply-to: aroid-l@mobot.org
To: aroid-l@mobot.org (Multiple recipients of list AROID-L)
Dear Eduardo,
Am pleased that someone found the observations on Taccarum weddellianum
fruit of interest!
As a follow up, a few more notes on this interesting plant!---.
When Bobby`s plants bloomed in late spring, we tried two methods of
pollenation. The pollen was produced in long, rope-like yellow strands,
sort of the texture of moist flour-dough, and was difficult to 'handle' and
transfer to the stigmas, and did not seem to adhere very well to them. We
therefor pollenated two inflorescences, one by just applying this pollen
'paste' to the stigmas of one spadix, and on another I cut back the
paper-like spathe to fully expose the female zone, and put as much pollen as
I could all over the stigmas, then wrappen the spadix in plastic wrap! By
the way, we had several (4 or 5?) infloresences to work with!.
The plastic-wrapped spadix developed almost all of it`s fruit, while the one
we did not wrap only developed around 50% of it`s fruit.
While cleaning more seed yesterday, I confirmed that all the fruit I opened
had five locules/sections within each berry, and that most locules contained
one seed per locule, but that a few locules contained two viable seeds, and
that several had a viable seed together with a seemingly smaller non-viable
seed. In some locules the seed were positioned side by side, and in others
one above the other. There were only one locule with two seeds on any one
berry, I did not find any berries that had more than one locule containing
two seeds. I found no more than five locules per berry.
I`d like to once more emphasize how 'fleshy' these LARGE berries are, and
that they must provide a substantial attraction and source of food to
whatever the animal or bird may be that is attracted to them!
Julius
>>Dear Julius,
Thanks for your marvelous comments about the seeds of Taccarum
weddellianum. In fact, reproductive biology of aroids is still poorly
undestood, mainly when the subject is the tribe Spathicarpeae. I hope more
people feel encouraged to describe personal experiences and observations
with aroids.
Taccarum seems to be most closely related to Asterostigma, and DNA
information agrees with this supposition. However, the red berries of
Taccarum weddellianum doesn't seem to match any other tuberous species of
Spathicarpeae. All Asterostigma species I could observe have
withish/yellowish berries, sometimes with very small spots in carmine. Even
Taccarum warmingii has "Asterostigma-like" berries, i.e. they are yellow or
cream, with very small carmine spots. They are firm-fleshy and smell like
Philodendron fruit, i.e. they have some kind of butyric acid flavour. I
suppose they are dispersed by small mamals and maybe bats. Unfortunately,
the berries of the other Taccarum species are not known in fresh conditions.
I have seen unripe fruits of T. peregrinum and they are somewhat similar to
unripe fruits of T. weddellianum, but I really don't know if they will be
similar when ripe. Maybe Taccarum weddellianum have started his own way in
the attraction of vectors. Just like you, I think that the vector of T.
weddellianum seeds are birds.
Scarlet fruits are not unknown on "Spathicarpeae sensu lato". I have
been revising this tribe for some years and I am convinced that
Dieffenbachia and Bognera shouldn't be out of this tribe. They share with
the tuberous Spathicarpeae many similarities, so they may be put in a
expanded Spathicarpeae soon. As many of you know, berries of most
Dieffenbachia species are orange or scarlet. Maybe it has occurred a
evolutive reversion in Taccarum. Who knows?
Dispersion by ants probably occurs with Spathicarpa and I have seen
ants
carrying those small seeds in the limestone outcrops of Central Brazil.
Berries (?) of Spathicarpa are just like a green membranous envelope
surrounding the seeds. There is no pulp.
The presence of two seeds per locule has been cited only in Mangonia.
But it is also known for Spathantheum. In fact, if you take a look at the
illustration of Spathantheum in the Genera of Araceae, you can see that the
artist observed and drawn two ovules, but the authors cited the genus as
having only one ovule per locule. Maybe it is not so uncommon in the tribe.
Most species of the tribe Spathicarpeae are poorly known, and even those
that are supposed to be well known, most observation were carried from only
a few population (usually only one). We have a lot of work to be done!!!!
Once again, thanks for your observations. Just keep them coming!
Best wishes,
Eduardo.<<
>From: "Julius Boos"
>Reply-To: aroid-l@mobot.org
>To: Multiple recipients of list AROID-L
>Subject: Taccarum fruit.
>Date: Sun, 15 Oct 2000 13:33:46 -0500 (CDT)
>
>Just a note to share an interesting experience I had this AM while cleaning
>the ripe fruit of a Taccarum weddellianum which I pollinated earlier this
>year at my friend Bobby`s collection. As you may have read, I had the
>luck
>some time ago to also clean the ripe fruit of Synandrospadix vermitoxicus,
>another genus that belongs in the same in the Tribe Spathicarpeae.
>
>The berries of Taccarum were large scarlet-red in color, about the size,
>color and shape of a 'cherry' tomato, and had a thin, papery skin. Under
>this skin were the individual fruit, between five and six, arranged almost
>exactly like the segments of a mandarin orange when its skin is removed.
>They had a red, fleshy, thick, and very moist outer layer, tasted (!)
>sweet, pleasant. Most fruit contained one seed enclosed in a tough
>membrane
>which I had to puncture and slit with a sharp, pointed knife, but several
>contained two seeds within one fruit. In some berries there would be one
>or two or three fruit that though juicy, did not contain a seed.
>
>In contrast, the fruit of Synandrospadix ripened a pale yellow, and were
>juicy and also sweet, BUT each seed had a conspicuous cream-white tough
>fleshy structure on its end, this structure is called a strophiole, which
>is
>thought to be a food attractant to vectors, perhaps in this case ants.
>This strophiole was not present in Taccarum.
>It is interesting to note that in Taccarum a single fruit/segment could
>contain two viable seed, contrary to the description of the Tribe of having
>only one ovule per ovary locule (except Mangonia).
>It is also interesting to speculate what the vector could be that is
>attracted to, eats, and so distributes these fruit. The color red, the
>fleshy sweet tasting fruit, and the large seeds with a thin outer covering
>seem to point to a bird with a rapid digestion that would pass these rather
>delicate seed through and out in a short time. Does anyone out there has
>any ides as to what this bird (or mammal?) could be??
>
>Sincerely,
>
>Julius
> >>
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