Re: Poison Ivy / Poison Oak
Bob Gerrish (u-rpg@NTA.COM)
Mon, 12 Jun 1995 09:10:00 -0700
On Mon, 12 Jun 1995, Gary Sherwin wrote:
> It is my understanding that the "P.I.Gigantus" and the often argued
> poison ivy vs poison oak variations of G.Toxidendron, (I forgot the genus)
The genus is Rhus. Same genus as poison sumac (and BTW same family,
possibly genus as cashew nuts).
> are nothing than environmental varriants of the same species. The
> ivy / oak differentiation is driven by soil alkalinity and the size variation
> is driven by fertility and available water. At least that is how it was
> described to me by my Botany prof Dr. Bell (Now Deceased) at the University of
> Pittsburgh. This means that if you were the adventurous type (and a little
> nuts) you could take seeds from any of the above plants and plant them in
> the different conditions, and find that they magically transform into the
> local "subspecies" or "variety"
This is something similar to what my first Plant Taxonomy / Botany teacher
(Mr. Rufus Kaiser of Centralia Community College, Centraila WA) told us.
He was one of the two leading plant taxonomists in the state and had a
running argument with the other one (Hitchcock of the U of W) about
this. Mr. Kaiser took us to a patch in eastern WA where "poison ivy" was
growing on one side of the patch, "poison oak" on the other side and
variations in between. Out here they are supposedly different species,
(R. toxidendron and R. diversoloba, respectively if I remember
correctly.) Mr. Kaiser argued that they were not even subspecies, but
only variations due to soil conditions.
Terry Howerton Sakima Group, Inc. SCOUTER Magazine Kansas City