Re: Arum conncinatum - experiences?
Here about 200 miles south of you, I have grown a plant for about 10 years
originally from NARGS seed labeled "Arum nickelii", which I'm told is
synonomous with A. concinnatum.
I have no reason to believe it isn't what it was labeled, but haven't
really verified it and thus am cautious - the one year I got an
inflorescence was before I had a good key. Looking at Peter's book a
moment ago, I should pop it out of the ground and take a look at that end.
(I planted it in a pot to facilitate moving it later, so I can't really
tell if it's running or offsetting from the surface.)
The leaves do have a few of the cloudy silver markings described, for
whatever that's worth. It is clearly less cold-tolerant than my A.
italicum. The foliage will take quite a bit of frost, but at about -11 C
(+12 F) it starts to suffer, and by -15 C (+5 F) all foliage dies. A.
italicum is barely fazed by this. A. italicum, once flowering size, blooms
pretty reliably here, while as I mentioned I've gotten only one
inflorescence from this in a decade. It has certainly not gotten as large
as described, nor even quite as large as my largest italicums. I'm sure
it's not really happy here, as it hardly ever gets a full growing season,
and I've been pleased that it even survives. It has been here long enough
to have had to tolerate overnight lows of -25 C (-15 F) or slightly worse.
I think I will pop it out of the ground, take a good look at the geophytic
portion, and then see if I can find a more suitable spot ... thanks for
reminding me of it.
-- Steve Marak