group,
I was wondering if there is a definitive way to tell versicolor from
robusta. I thought the length of the seed pod would do it (with the
pods being longer in robusta), but was not able to correlate that
precisely with the cvs I have. Of course robusta is supposed to be a
bigger plant, but some of Tony Huber's collected versicolors are pretty
large, too. Any help?
In my area (central NY state) I can use the mid-rib in the foliage
of pseudacorus to distinguish it from versicolor; it's so obvious you
can usually tell them apart from ten or twelve feet away. Pseudacorus
also tends to have a brighter green color, whereas versi is a little
glaucous.
Ken
z*@umich.edu wrote:
>
> The range of versicolor and virginica overlaps in the upper half of
> Michigan's lower peninsula, so below is the relevant key and text from
> Voss' Michigan Flora. I especially like the exserted ovary character
> as it's easy to see even in photos, and seems to work for all my
> photos of wild irises in Michigan. I have no idea if the key will work
> on more southern forms of virginica, but it's worth checking out.
>
> Sean Zera
> Zone 5b/6a
> Ann Arbor, MI
>
> -----------------------
> Voss, E. G. 1972. Michigan Flora- Part I Gymnosperms and Monocots.
> Cranbrook Institute of Science Bulletin 55 and University of Michigan
> Herbarium, Ann Arbor.
>
> Base of expanded portion of sepal with a bright yellow spot, finely
> pubescent with hairs as long as the thickness of the sepal; outer
> spathe bracts of uniform texture and color; seeds round to D-shaped,
> irregularly (but shallowly) pitted... Iris virginica
>
> Base of expanded portion of sepal at most with a greenish-yellow spot,
> with papillae shorter than thickness of the sepal; outer spathe bracts
> with the marigns generally darker and more shiny than the rest of the
> dull surface; seeds D-shaped, with a ± regularly pebbled surface...
> Iris versicolor
>
> The cauline leaves of I. versicolor are shorter than the tops of the
> inflorescence, while in I. virginica the cauline leaves frequently
> overtop the flowers. The ovaries of I. versicolor (at anthesis) are
> somewhat shorter (1-2 cm long), at least one of them exserted on the
> pedicel beyond the tip of the spathe; while in I. virginica the
> ovaries (before forming fruit) are 1.5-3 cm long and usually are not
> exserted. The bases of plants of I. versicolor are more frequently
> flushed with purple than are those of I. virginica, which are
> generally brown. But all of these characters are variable, and several
> must often be considered before identification can be made. A hybrid
> between the two species has been described as I. xrobusta Anderson, on
> the basis of two colonies studied near St. Ignace and at Engadine
> [Mackinac County].
> -----------------------
>
> Quoting Laurie Frazer <lauriefr@localnet.com
> <mailto:lauriefr%40localnet.com>>:
>
> >
> > On May 20, 2008, at 12:36 PM, James Harrison PhD wrote:
> >
> >> Now would someone tell me an easy way to distinguish versacolor
> >> from virginica? Or, are they so interbred in garden plantings that
> >> there is a spectrum?
> >
> > I believe it was Bob Pries who told me that the seed pods on
> > versicolor are 6-chambered, while those on virginica are 3-chambered.
> >
> > Laurie
> >
> >
> > ---------------
> > laurie@lfrazer.com <mailto:laurie%40lfrazer.com>
> > Shadowood - http://lfrazer.com <http://lfrazer.com>
> > The Irises of Shadowood - http://lfrazer.com/iris/
> <http://lfrazer.com/iris/>
> > Wallplates With Panache - http://lfrazer.com/wallplates/
> <http://lfrazer.com/wallplates/>
>
>
