poison ivy

If you haven't had the misfortune to hear me drone on about my current poison ivy run-in at Kloempken Woods last Sunday, I apologize for crashing in on your sanctuary with my further ranting. I can't help but share the information, because the sum of all my poison ivy experiences is developing into a personal mission.

Not that we'll be working in the same area when we head out to Kloempken on Wednesday, but I considered the option of not going back since getting through my worsening Rhus Dermatitis is of super urgency right now compared to just about anything. But I think I'm more interested in facing my nemesis. I at least have little business taking ay opportunities to practice identifying the various sneaky morphologically different forms of the plant.

I found this site last night and enjoyed the variety of photos featuring the all the cheating modes used by poison ivy. There's also a helpful quiz which emphasizes recognizing the ivy when it's nearby and mimicking other plants. One funny aside: in the advanced i.d. quiz, one of the trickster plants is jewelweed, which I'm assured is native and very abundant in disturbed areas. Hence the reason it can be misidentified when trying to locate poison ivy. The funny part is that I've twice discovered recommendations of jewelweed as a remedy for the poison ivy itch. So if you know of any jewelweed let me know and I'll try some homeopathy.
http://www.blogger.com/login.do

I also think I may spotted some potential plants in my neighborhood so let me know if I've got it right or have misidentified it:

I think this plant is faking me out - the leaves arent's quite a threesome

The three-leaved beast on the right edge is the suspect.

Apparently the plant loves the edges of habitats and roadsides. Last Sunday the group worked in area that was a forest edge along a roadside! Clearly I'm idiot for not paying attention to some of blatant warning signs.

Some other interesting facts about the urushiol - the chemical in the plant's oil that initiates the dermatitis response:

• Urushiol, once absorbed into lower layers of skin, becomes bound in dermis cell membranes and if left alone would cause no health problem. The entire chain of events of having poison ivy is an unwanted immune mechanism that is apparently overzealous and misguided (which = allergy)!

• Urushiol has been investigated and approved of research concerning chemical warfare. http://www.centerwatch.com/patient/drugs/dru606.html

• Poison ivy is in the taxonomic family Anacardiaceae containing relatives such as pistachio, cashew, and mango. Incidentally, the "poison-ivy mango connection" is a research topic of interest about people who are sensitized to urushiol and then handle mangoes and incur Rhus Dermatitis. Apparently mango contain urushiol:

Contact Dermatitis. 2005 Jan;52(1):3-5.
Exploring the mango-poison ivy connection: the riddle of discriminative plant dermatitis.
Hershko K, Weinberg I, Ingber A.
Department of Dermatology, Hadassah University Hospital, Faculty of Medicine Hebrew University, Jerusalem 91120, Israel.

A relationship between sensitivity to poison oak or poison ivy and mango dermatitis has been suggested by previous publications. The observation that acute allergic contact dermatitis can arise on first exposure to mango in patients who have been sensitized beforehand by contact with other urushiol-containing plants has been documented previously. We report 17 American patients employed in mango picking at a summer camp in Israel, who developed a rash of varying severity. All patients were either in contact with poison ivy/oak in the past or lived in areas where these plants are endemic. None recalled previous contact with mango. In contrast, none of their Israeli companions who had never been exposed to poison ivy/oak developed mango dermatitis. These observations suggest that individuals with known history of poison ivy/oak allergy, or those residing in area where these plants are common, may develop allergic contact dermatitis from mango on first exposure. We hypothesize that previous oral exposure to urushiol in the local Israeli population might establish immune tolerance to these plants.

***The above abstract was all I could access of this article since DePaul is not known for their adequate journal subscriptions, so I wanted to see what other research has been published in the journals we can access:

A Comparison of Nutrient Concentration in Two Poisonous and Three Nonpoisonous Species of Sumac (Rhus spp.)
Kathleen C. Weathers; Thomas G. Siccama

Compares N, P, K, Ca, Mg, Na, Zn, Cu, and Pb levels and finds that poison ivy (and other poisonous species) do have higher levels of N and P in fruits, but that these elements are not present in urushiol and contribute nothing direct to the poisonous traits.

Host Preferences of Rhus Radicans (Anacardiaceae) in a Southern Deciduous Hardwood Forest
Sharon M. Talley; Robert O. Lawton; William N. Setzer
Ecology, Vol. 77, No. 4. (Jun., 1996), pp. 1271-1276.

Abstract

Rhus radicans, a root-climbing liana, is not distributed randomly among potential host tree species in old-growth mixed mesophytic forest on the southern Cumberland Plateau of north Alabama, USA. Vines are more abundant than expected on Carya ovata and Quercus rubra, but less abundant than expected on Juglans nigra, Acer saccharum, and Sassafras albidum. Seed germination and early seedling growth in the presence of bark extracts suggest allelochemical interactions may influence the observed host preferences.

Foods of White-tailed Deer, Odocoileus virginianus, in Martin County, Indiana
Dennis J. Sotala; Charles M. Kirkpatrick

Besides some botanical/identification book reviews, that's all the research that I found on JSTOR using an exact phrase search for poison ivy and key wording urushiol. Sounds like a ready-made research intersection for collaboration between research and land management! Anyone up for the challenge...let me know.

**********************************************************************************
And finally, for the least-helpful identification award, I present for your consideration U.S. governmental work (USDA)...

Poison Ivy

http://www.fda.gov/fdac/features/796_ivy.html

• Grows around lakes and streams in the Midwest and the East - could this be any vaguer, not to mention misleading? Why do they not mention woodlands, where no water is present, parking lots, vacant lots, etc?
• Woody, ropelike vine, a trailing shrub on the ground, or a free-standing shrub - this tip I actually find superbly helpful and can vouch for the presence of specimens matching this description perfectly at Brookfield Zoo in the tree stands between Ibex Island and Habitat Africa (so don't offroad around the zoo; and by the by, my last Rhus Dermatits event was from contact with poison ivy mixed in with grapevine permeating the parking lot fences at the zoo)!
• Normally three leaflets (groups of leaves all on the same small stem coming off the larger main stem), but may vary from groups of three to nine - I'm sorry, three to nine?!?! That's quite a range.
• Leaves are green in the summer and red in the fall
• Yellow or green flowers and white berries - apparently most sources agree that you'll never see the flowers due to their tiny size.