Arisaema Id

[Kristl Walek]

I am posting this on behalf of forumnist Rob Illingworth in cold Thunder Bay, Ontario.
He grew this Arisaema sp. from ACE seed and it has proven quite hardy in northern Ontario (which I would guess is at least -35C or colder).

Foliage grew to about 1m this year.

Any ideas of id please, considering the hardiness factor.

As I have seed in front of me, there is my vested interest in knowing as well.
Being able to offer seed of other Arisaema species that might prove hardy in the very cold areas  of Canada or elsewhere is a real benefit.

[annew]

Did he have the collection number?

[WimB]

Kristl,

I would say Arisaema consanguineum subsp. consanguineum but I'm not 100% sure. I'm sure it's in the section sinarisaema, though.

[Kristl Walek]

that was my first instinct---but i know rob already grows consanguineum (in pots at least that he takes indoors each winter) so i assume he sensed a difference. however, it *is* a variable species. i have emailed him to see if he still has an ACE number.

[Pascal B]

Indeed very likely one of the many forms of Arisaema consanguineum, a species that is notoriously variable and very widespread. The higher altitude forms tend to have more numerous and narrower leaflets than the lower altitude ones. In the new FoC consanguineum is synonymised under erubescens. That view is highly debatable (and in my view incorrect) but the list of species they all synonymise under the same name shows also Li Heng and Jin Murata are struggling with this polymorph species. Given its variable nature, naming subspecies is a dead end, you probably end up with dozens, it is one of the species that is in desperate need of molecular analysis.

[Kristl Walek]

and indeed, Pascal, if he has one of the higher altitude forms that may also explain the fact that it is so hardy.

i lived in a similar climate to rob before moving to warm Nova Scotia---and most forms of consanguineum i tried were NOT hardy for me.

[Pascal B]

It is surprising given the fact that consanguineum in Nepal, where the holotype comes from, only grows at around 2000 meter altitude. Going further east the forms in Arunachal Pradesh also do not grow much above that altitude but once the species reaches China it can occur upto 3500 meter altitude or more. It also grows in a lot more different habitats and 3000+ meter altitude is the altitude where most species of section Sinarisaema generally don't even consider growing.

Saying that, hardiness experiments done by Tony Avent show that even species considered subtropical can survive the winters in N Carolina outdoors so microclimate and growing conditions also can influence hardiness. But how wet or dry are the winters where you lived Kristl? Because that's what usually kills Arisaema during the winter: excessive moisture.

[Kristl Walek]

Pascal....Tony Advent is considered to be in the tropics from a perspective of North American cold hardiness.  

I think both Rob and I had similar winters; except he has a lot more reliable snow than I had. Very cold (-35 to -40C); sometimes snow during the coldest periods, sometimes not--just solidly frozen grounds. Rob, I believe with his more reliable snow cover and better microclimates than I had would be more successful.

In the 20 or more years of trying dozens of species in that climate---my successes were limited to: amurense, triphyllum, dracontium, sikokianum. flavum.

The amurense, from a start of a dozen seed grown plants, eventually over 10 years or so, had solidly filled in an area about 30 x 20 feet or more (under competitive sugar maples). Then I lost the entire colony to Arisaema rust (the other two exotic species as well).

[Paul T]

Kristl,

The Aroid Society would probably be interested to hear your experiences.  Their hardiness list only shows amurense down to -15'F, for example, although they're wanting no snow cover I think?  Your info could be quite useful to them?  I'm not a member, but I do check their hardiness list at times when people are discussing hardiness issues.

[Pascal B]

Pascal....Tony Advent is considered to be in the tropics from a perspective of North American cold hardiness.  

I know. But with his silly experiments he has proved that some species can surprise us for hardiness, at least under his conditions. That you report having succes with sikokianum for instance is also a surprise as this species is a relatively low altitude temperate species and I am sure I will kill it in the garden when the temps go below -10C or after prolonged periods of frost. It is also allergic to winterwet. Snow cover generally is very good insulation but in W Europe the winters are not constant so what one day is a good snow cover could be a soggy soup that will kill the tubers the next day. Only surplus stuff I plant in the garden, the rest is grown in pots and overwinters in 3 "Arisaema" fridges in boxes with vermiculite.

But it could very well be the consanguineum of your friend Rob will not survive -10 C here in Holland. Reported hardiness is more a guideline than a guarantee...