Arisaema

[Philippe]

Hi

I've got only very few experience with arisaemas. For the moment the only one I tried from seed was the flavum, which showed no problem at all to germinate and grow on.
For a few weeks I started A.thunbergii seeds on moist sphagnum. Little and encouraging white tips rapidly appeared on the 6 seeds I had got, so I decided it was time to place the emerging seedlings into an appropriate medium, at about 1 cm under the surface ( temperatur never under 4/5°C).
Since that time, nothing new. And it's already been now 4 weeks ago. So what's going on? Were those white tips only the first roots, which would mean it is normal at all if I don't see anything coming above yet? ( nothing coming out the drainage holes either)
I just hope I didn't do anything wrong with those 6 seedlings?

[Ulla Hansson]

I think it's too cold. I grow my Arisaema seeds around 20 degrees.
 I do not know if it works for all varieties.

[Philippe]

Thank you Ulla.

[DavMac]

Phillipe,
When an Arisaema germinates the cotyledon emerges from seed and stays underground (hypogeal germination). Most species then produce a simple aerial shoot (an eophyll) above ground and the hypocotyl (stem region below the cotyledon)  produce roots and develops a small tuber by the end of the growing season. Some species, such as Arisaema thunbergii, don't. In those species germination occurs but no eophyll forms. There is enough energy stored in the seed for the hypocotyl to produce a small tuber though.

Other species that do this include Arisaema elephas and Arisaema lobatum.

So pot up your seed and next season you should see an above-ground shoot.

David