IAS Aroid Quasi Forum

About Aroid-L
 This is a continuously updated archive of the Aroid-L mailing list in a forum format - not an actual Forum. If you want to post, you will still need to register for the Aroid-L mailing list and send your postings by e-mail for moderation in the normal way.

  Amorphophallus Morphophallology
From: "James W. Waddick" <jimjim at sky.net> on 1997.02.21 at 09:15:09(410)
Dear Wilbert et al;
Dept of dumb questions.
I've always thought the appendix of the spadix (the terminal
portion above the male floral zone) was olbviously the visual target in
pollination. It is often the largest portion of the spadix, usually the
most colorful etc etc.
In your admirable Aroideana guide to the genus you mention that the
appendix is also the source for scent and exudes droplets of fluid and may
be the source for all the heat.
It does make sense (scents) more likely for the portion that warms up to
exude its liquid perfume, warm it up and be situatuated above the spadix
-or at least at the top to do all this and get maximum scent exposure.

So my question.... Is all this supposition true? Does the appedix
fluid also have any attraction to insects (sugars or?) ? And it seems that
the appendix seems to have the greatest range of variation of any spadix
components. Eh?

+More
From: "NAME \"Wilbert Hetterscheid\"" <W.HETTER at pbga.agro.nl> on 1997.02.21 at 19:42:05(411)
Dear Jim,

The appendix is certainly the most variable part of the spadix morphology
of Amorphophallus. The heat development is found both in the male zone
and the appendix, which is not too surprising as the appendix is in fact
one large collection of fused and non-functional male flowers (a synandrodium).
Therefore appendix and male zone are in fact continuous and both produce
heat. The appendix fluid may be a means to wet the visiting insects and get
pollen to stick to them. It has been suggested for Philodendron I think
pers. comm. Tom Croat) and could equally well apply to Amorphophallus, yet
not many species actually do it. The exposure of the appendix has always
led me to believe it is some kind of flag. Maybe beetles (the pollinators)
are attracted by infrared! I actually don't know if beetles are but I recall
that dung beetles are attracted by light sources at night but I don't know
if it's the infrared heat-radiation emitted by electric lights that attract
them. It seems sure that the heating also helps in volatising the chemicals
that make-up the scent.

These were some thoughts.

Happy infrared dreams!

+More
Note: this is a very old post, so no reply function is available.