Arisaema-offsets

[P.Bruggeman]

Dear all,

>From experiences with Arisaema. sp in my own collection I can tell that the
following species produce bulblets:
A. amurense
A. brevipes
A. candidissimum
A. consanguineum
A. costatum
A. fargesii
A. flavum
A. formosanum and var. bicolorifolium
A. franchtetianum
A. griffithii
A. heterophyllum
A. intermedium
A. jacquemontii
A. kiushianum
A. lobatum
A. nepenthoides
A. ostiolatum
A. ovale
A. polyphyllum
A. propinquum
A. ringens
A. sazensoo
A. sikokianum
A. speciosum and var. mirabile
A. taiwanense and var. brevipedunculatum
A. thunbergii (all 3 ssp.)
A. tortuosum
A. utile
A. verrucosum

The plant known in the trade as A. pangii (which might be a form of A.
lobatum) also produces bulblets (up to 16 in 1 season). A. sikokianum and
it's close relatives (A. sazensoo and A. engleri) are able to produce
bulblets but generally are very shy in doing so. Last season was the first
time I ever had bulblets on A. sikokianum and they were tiny.

The following species I have found to be stoloniferous:
A. auriculatum
A. ciliatum and var. liubaense
A. concinnum (a very illustrative picture of A. concinnum-stolons can be
found on Paul Christians' site)
A. erubescens

I have never seen any stolons on my A. galeatum but then again, I have never
seen bulblets either. I grow all my Arisaema in pots nowadays and I
generally find that they produce more offsets in pots than they do in the
open. I never use any force to detach offsets from the main tuber. You
sometimes see bulblets still (semi-)attached to the main tuber which should
be big enough to start a life of their own but you better leave them on. At
the end of next season they have increased in size even more and probably
have a better change of producing growth themselves. Offsets from section
Franchetiana (A. candidissimum, A. fargesii, A. franchetiana etc.) can often
be found well attached from the mother tuber and start to grow well next
season. The offsets from the stoloniferous species do the same as well as
those of A. thunbergii, A. nepenthoides and A. tortuosum. Most of the other
species I find more difficult. The offsets either die or stay dormant.
Rarely they "wake up" and then I think I have been rather lucky instead of
having the feeling I have done something right. It is all very well if you
get lots of bulblets but if they don't do thing, what's the purpose of
producing them? I have tried various methods of trying to awake them but
thus far in vain. Maybe they contain a growth inhibitor like those found in
seeds. Could there be a glibberilic acid-equivalent for bulblets? There must
be a controlled way of waking them up but what is it?

Pascal Bruggeman
Holland