Amorphophallus titanum

by Bernhard Strolka

Here are three pictures of an Amorphophallus titanum held in hand by a friend of mine who is a Ph.D. student at the Institute of Floriculture, Tree Nursery Science and Plant Breeding at the Hanover University. He abuses the greenhouse of the Institute to grow his titanum and obviously the plant likes it.

The plant is from tissue culture and he got it from me in August 2001 when the plant was about 4 inches high. It made, I think only three leaves one after another without dormancy in between. The height of the leaf roughly doubled each time.

The other day he noticed a small leaf at the base of the youngest petiole and he hopes that it belongs to an offset. As far as I know titanum does not grow offsets, but I wanted to get some feed back from others about this small leaf in order to tell him what the experienced aroiders think about it.

The first picture is from May 2002 and the other two are from early September 2002.

Update - June 2006


Today (29th June, 2006), I would like to tell what came out of the funny leaflet.

As suggested it was just another leaf, which looked like this after a while.

However, we could not examine the tuber, since probably one of the gardeners (a certain Mr. Unwise) who did not know about titanium being a tuberous plant threw it on the compost when the leafs wilted :-(

In the discussion it was an "Aha" from Petra Schmidt, when she read that this plant was tissueculture derived. She observed some differences in tc plantlets vs. seedlings.

However, tc-derived plantlets regularly develop normal.

In 2001 I gave a tc-derived plant to the Berggarten, Hannover, Germany and this plant looked like this after 4 years.

Where tc-derived plants can finally end after 18 years can be seen here:

( Yes, the triple-flower-titanum from May,14th 2006 in the Botanical Garden Bonn, Germany, came from tissue culture, too. It was regenerated by the group of Prof. Kohlenbach in 1986; BTW the small guy in front of the plant is me...)

I took some of my puppies with me to motivate them ;-)


Update August 2007:

Aroiders, after one year has passed there are three things I would like to share with you.

1. The titanum at the Berggarten, Hannover, Germany went ot sleep in autumn 2006. The tuber weight about 3.9 kg and had a diameter of about 25-30 cm.

During winter it grew a new leaf and on August, 7th, 2007 I could take these photographs:

2. In August 2006 I transferred a batch of my via tissue culture propagated A. titanum to the greenhouse.

I used the following two substrates:

a) A ready mixed potting substrate called 'Einheitserde P' (EEP) here in Germany; 60 % 'white' peat, e.g. coarse and fiborous; 40 % clay; 1.5 kg/m? mineral fertilizer

b) 1/3 each of 'Einheitserde P', perlite and charcoal 2-4 mm; this is roughly the mix recommends for Amorphophallus

The plants were fed with every watering with 0.07 % horticultural fertlizer for Phalenopsis.

First the plants in EEP looked better - the ones in the mix were paler, probably due to the initial lower fertilizer content of the mix and maybe absorption by the charcoal:

After a few month this changed and finally the plants in the mix were a little bit taller and had a much better developed root system and survival rates were much higher, too.

After about 12 month many plants went dormant. To give an impression here are two pictures of the tubers grown in EEP and the mix, respectively.

All in all the mix was superior to the EEP.

However, skilled gardeners might be able to grow titanum in EEP as well, but the well draining mix definitely helps in the acclimatisation and growing of in vitro propagated titanum transplants.

3. Now three pictures of a A. titanum grown from seed in 2003, as far as I know obtained from the Botanical Garden in Bonn ( ).

The question is why this plant is variegated.
The gardeners of the Berggarten suspect a virus equivalent to one that causes variegated plants in Abutilon.
I would rather vote for an L2 chimaera.
Or should transposons be involved????

Good growing,

Please send your comments to Bernhard Strolka.