fertilization mystery (?)

[Mary Lamb]

We live on a small city lot in Seattle, and there is room for only a few
arisaemas. This year there were blooms on 3 A. triphyllum, A. sikokianum and
A. taiwanense (1 each). Later in the season, after the inflorescences of the
earlier plants had wilted,  A. concinnum appeared with two blooms: a large
vigorous set of two leaves and inflorescence and a nearby smaller but
similar combination. A little later, in another part of the garden, A.
tortuosum appeared with plenty of leaves but only one inflorescence. Now
both A. concinnum and A. tortuosum have fruiting spikes.

I didn't inspect the spadix on any of these plants, but I can imagine the
smaller of the two A. concinnum would have been the pollen source in that
case. What about A. tortuosum? Is that species regularly self-fertilizing?
(Is this apt to be one of those "false pregnancies" described in the
Gusmans' book?)

Mary Lamb