Re: Amorphophallus titanum flowering at Selby Gardens
I was very happy to see your note on Aroid-L about your twin Titan Arums;
CONGRATULATIONS! I may not be able to be there for the first inflorescence
opening due to a trip to London at month's end for the Chelsea Flower Show,
as well as a Kew visit, but hopefully the inflorescence phenology of your
second tuber will wait for me. I saw the nearly open Fairchild
Amorphophallus titanum inflorescence last year, and it was incredible!
You asked me some months ago about Am. titanum controlled pollination, so
here are the essentials on the pollination of your twins. This information
is from my personal experience on pollinating other Amorphophallus species,
as well as the information from Jake Henney's learned experience in
ornamental aroid controlled pollination. The technique discussed in the
following is not precise, as there is probably more art than science
involved. And others may have other methods that have worked too; anyone
else please do give their input too. Wilbert gives an interesting account
of general Amorphophallus pollination in situ at
Amorphophallus pollen is not physiologically amendable to long term storage,
unfortunately. It may last a month or so under the proper storage
conditions, but that may even be pushing the potential of the viability.
However, the window of opportunity for pollen viability with human
intervention is far greater than the female flower receptivity as I am sure
you are aware of; the stigmas will be at peak receptivity for just a few
The principal reason for this fleeting pollen viability is that it is
trisomic, i.e. it has three nuclei rather than the more typical disomic
pollen in the majority of the plant kingdom. This factor along with other
genetic, physiological, and morphological factors make for a short lived
pollen. But in this case, in the native Sumatran rainforests that the
Amorphophallus titanums are endemic, it gets the job done so to speak. This
same pollen type also exists in other aroids from that region like
Aglaonema, as well as others that may be undefined as of yet. So, think
high humidity, and in order to prolong viability, a bit cooler conditions
than the pollen would normally experience so as to slow down the metabolism.
This is how you should collect, store, and finally apply the pollen to the
receiving female flower stigmas:
1. The pollen must not get wet or moist, nor should it be allowed to dry
2. Collect the pollen with a clean instrument to minimize microbial
contamination that could cause problems during the cool, moist storage
conditions. This "instrument" could be a spatula or small spoon that was
flame sterilized. Try to avoid using fingers if possible.
3. Pollen collection could be facilitated by cutting a small access into
the base of the spathe in the region of the male and female zone of the
spadix. The Atlanta Botanic's horticulturists did this with their
inflorescence last year, and you can see the technique at
4. Place the pollen into clean, dry glass containers that have closures
that can be left loose fitting to allow gas exchange. Perhaps you could use
test tubes and the plastic caps that go with them that you may have left
over from the days of the Eric Young Micropropagation lab operation at
Selby. There will be a lot of pollen shed, so collect as much as you think
you might need. But do not over load the containers with pollen as this may
cause adverse physiological conditions, i.e. anaerobic conditions,
mechanical squashing, poor gas exchange, etc. Again, the closures for the
pollen storage containers should be loose fitting to allow gas exchange.
5. Put the containers of pollen into another clean container that has a
moist, but not wet, clean paper towel on the bottom to promote high
humidity. This container could be, for example, a Rubbermaid or Tupperware
tub with a tight fitting lid. How ever you decide to engineer the storage
containers, keep in mind that you want the pollen to remain in a high
humidity environment, but the pollen should not get wet.
6. The next critical ingredient in this botanical feat you are attempting
to accomplish is to keep the pollen at cool temperatures until you are ready
to apply the pollen to the recipient stigmas. Cool temperatures in this
case means a refrigerator at about 45 to 50 F (7 to 10 C). Try not to go
below 40 or above 55 F (below 4 or above 13 C) as this could cold damage the
pollen, or hasten the pollen metabolism via warm temperatures respectively,
and subsequently diminish viability in either case. Too cold is probably
the worse of the two extremes though.
7. Allow the pollen to reach ambient temperatures before pollination.
8. For applying the pollen, use a clean, moistened brush to apply pollen to
each of the stigmatic surfaces.
9. After you finish the pollination, you need to maximize humidity to as
near 100% as possible in the zone of the female flowers on the spadix for
the following 12 or so hours. Jake Henney does this on Dieffenbachia and
Aglaonema pollinations by loosely wrapping the spadix first with a damp
paper towel, and then enclosing this with plastic wrap. Perhaps damp paper
towels wrapped around the spadix appendix to effectively plug the funnel of
the spathe topped off with some plastic wrap would keep the humidity high to
promote the pollen germination.
10. You will know within a day or less if the pollination is successful as
the spadix will remain in place as the spathe degenerates at the end of the
Please do keep us posted on your progress, and please take good photo
documentation for all of us to follow your success.
Good luck, Scott
Mr. Scott E. Hyndman
Winter Park, Florida, USA
USDA Hardiness Zone 9b
>Subject: Amorphophallus titanum flowering at Selby Gardens
>Date: Mon, May 10, 1999, 5:24 PM
> Here is a copy of our latest press release. The largest bud is now showing
> spathe and spadix through an opening in the outer sheaths and is about 35
> inches tall, growing about 3-4 inches per day. Based upon flowering data from
> Fairchild Tropical Garden and Atlanta Botanical Garden, our largest bud
> should be open in about 10-12 days. The smaller may be up to a week later, so
> we are planning a pollination attempt. Stay tuned to our web site at:
> Donna Atwood
> Selby Gardens
> 8aa S. Palm Ave.
> Sarasota, FL 34236