What is the body plan or anatomy of poison ivy?
If I'm interpreting your question right, you want to know the physical structure of the Poison Ivy plant (which would of course come in very useful in avoiding the plant as well). I am actually going to begin by giving the link of an article I found on MyGardenGnome.com, which I believe answers your question very well: www.mygardengnome.com/articles/PoisonIvy.htm So the article states that some of the major distinguishing factors of the poison ivy are the "Three even leaves - each almost the size of your hand or palm - growing on medium length petioles with an almost glossy red shine to the upper surface. Hairy growth from the shaft of the vine is also a commonly recognized trait". To add to the details about the hairs, the article also states that "older "hairs" (lower on the vine) darken with age, and the newer, more active "hairs" are usually pink". As for the arrangement of the leaves, "three leaves grows on its own stem from the main vine", and "each leaf stem alternates". I suppose, I have restated some of the main points of the article itself which answer the question, but for further information about what makes a poison ivy so irritating, and what to do if you come in contact with it, then this article can also help answer those questions very well as well.
Answered By: Harman Sawhney