BSA Endorsement?

[Peregrinator 85]

My old time family doctor always said that you could do two things to a Poison Ivy rash:   If you washed it well, as soon as possible with warm water and Octogon soap, the rash would heal in ten days to two weeks.  If you treated it with Calomine lotion, it would heal in a week and a half to 14 days. 

I realize that this is a joke, but cold water is better because warm water will open up your pores.

[TAHAWK 1420]

In Illinois, we have always called this giant hogsweed.  There are two smaller plants (small being relative - they still can grow to at least half the height of an adult human) that have the same kind of photo-sensitive effect and are much more common.  Cow parsnip - Heracleum maximum has, like the giant hogsweed, white umbels.  The plant we call wild parsnip has yellow umbels and not only looks like the parsnip plant of garden and farm, it shares the same latin name: Pastinaca sativa - which suggests to me the wild parsnip is just parsnips that have "escaped" the farm and is now growing wild.  The domestic parsnip has the same photo-sensitive chemicals that lead to the rashes one can get after encountering giant hogsweed, cow parsnip and wild parsnip in the wilds so I wouldn't go bombing through a farmer's fields of parsnip either.

Can these plants cause permanent blindness or tissue death of all layers of skin - as in down to muscle tissue?