In message Mon, 20 Jan 1997 06:06:11 GMT,
riordan at werple.net.au (Roger Riordan) writes:
>rwhitehead at cix.compulink.co.uk ("Roger Whitehead") wrote:
>>>>>>> This phenomenon is also widely known in N Europe. (Scandinavia).
>>> The culprit there is Heracleum pubescens & H. sphondylium.
>>>> Several of the umbelliferae offend in this respect. ........
>> So, too, do various Citrus species, Scorpion Vetch
>> (Coronilla spp.), Fig (Ficus carica) and, of course, Rue (Ruta
>>>> And, of course, Rhus. The ornamental varieties are bad - I got a burn
> on my arm once, as bad as if I had touched it against my motorbike
> exhaust, when I brushed against one while cutting grass with a motor
> scythe, but the North American Poison Ivy (also a Rhus) is diabolical.
>>> Roger Riordan.
>Well, in my experience and what I learned while living in the US this is as
Poison Ivy - Rhus radicans - about 60 percent of the population has an
allergic reaction to it. But which 60 percent may change every year. It is
more on the skin and I treated it with liquid vitamin E and it lasted less
then a week.
Poison Oak - Rhus toxicodendron - much more sever in its effect and you may
have to go to the doctor for treatment.
Poison Sumac - Rhus vernix - I have seen the shrubs but stayed well clear of
them. I heard that if you are affected it can eat down to the bones and one
has to go to the hospital.
All of the above are not dependend on light input but are rather an allergy
reaction. Is 'photosensitization' to be considered an allergenic reaction?