Re: Iris setosa (response)
On Wed, 17 Dec 1997, Bill Shear wrote:
> One of the things
> >that bothers me about the occurence of I hookeri (= setosa var
> >canadensis) on the east coast of N America is how did it get there
> >from the west coast? Did it originally occur on the entire north
> >coast of an earlier N American continent and spread down the east
> >coast to Maine and the Canadian maritime Provinces? I would really
> >like to know. Anybody have enough geology to offer clues?
> The standard idea is that I. setosa was widespread in both NE Asia and
> across North America at various times during the glacial period. Glacial
> advance would have separated western and eastern populations, which then
> evolved enough differences to become separate species (Note that an animal
> taxonomist would not consider setosa and hookeri separate species if they
> could freely interbreed, but plant taxonomists use different criteria). If
> the separation occurred during the last glacial maximum, then hookeri as a
> species may only be a few tens of thousands of years old.
OK relative to that idea, do you think that I setosa would exist in
west Greenland or inFrobisher Bay or down the east coast of Quebec
and Labrador or Newfoundland?
> Where is I. tridentata in all this? Supposedly it cannot be crossed with
> setosa or hookeri, but is included in the same series or subseries. I have
> plants of this species in my garden but they are poor "doers" and have
> never bloomed.
I know you should not answer a question with another one, but how
does this species grow a bit further north?
It is found in N. Car., S. CAr., Ga. and Fla., separated by
> a definite gap from hookeri. Did the Japanese botanists who studied the
> problem of hookeri include tridentata in their work?
> Bill Shear
> Department of Biology
> Hampden-Sydney College
> Hampden-Sydney VA 23943
> FAX (804)223-6374
Diana Louis <email@example.com> <- private email address
Zone 4 Newmarket, Ontario, Canada
AIS, CIS, SIGNA, IRIS-L, Canadian Wildflower Soc.
URL for the North American Native Irises web page