[MAIPC] poison ivy identification question (Toxicodendron)

[Donna Ford-Werntz]

Richard, WV recognizes several species/vars. of poison ivy (all once Rhus radicans).  Original WV Flora says "innumerable forms of a perplexingly variable species."
Virginia flora & other new treatments have keys to the segregates, which are distinguished by leaf margin, adventitious roots/climbing (vs. shrubby), pubescence, etc.

Donna Ford-Werntz, Ph.D.
Service Professor/Herbarium Curator
Biology Dept., Box 6057
Life Sci. Bldg., 53 Campus Dr.
West Virginia Univ.
Morgantown, WV 26506
304-293-0794; biology.wvu.edu
________________________________
From: MAIPC <maipc-bounces at lists.maipc.org> on behalf of Richard Gardner <rtgardner3 at yahoo.com>
Sent: Saturday, June 17, 2023 9:27 AM
To: MAIPC Listserve <maipc at lists.maipc.org>; Listserv Umd Listserv <listserv at listserv.umd.edu>
Subject: [MAIPC] poison ivy identification question

I have been around poison ivy all my life and had at least one case of dermatitis from it every year. So I instinctively know what it looks like dormant, as a vine and most other forms. However, in the last week it hit home that there appears to be at least 2 different leaf shapes - a toothed/serrate leaf growing on the ground and a smooth margin when growing on trees. Am I correct?

Do we have poison oak growing in the mid-Atlantic? This question is what made me question the various forms of poison ivy. I know that according to theory the closer to an area that an organism evolves in the more diversity in form. In languages the original home of a language can be found by the diversity of words for a concept.

One interesting experience I have had with poison ivy is that when cutting thick vines on a tree with an axe the axe rang like a bell.

I use jewelweed (Impatiens capensis) fresh or preserved in isopropanol to reduce contact dermatitis. If I know that I have the urushiol oil on me I try to find a flowing stream and wash it off. When I get home or to a faucet I wash (hose off) exposed skin thoroughly. All clothing that has been in contact with it is turned inside out and washed several times. I dust my shoes with baby powder or any easily available fine powder such as white flour to absorb the urushiol.

                                                    Richard Gardner
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