Rob, the plant in question was Rhus typhina 'Laciniata', bought from a nursery and planted in my garden. It definitely was not Poison Sumac, and there was no Poison Ivy in the area. The first time I was ill, I didn't know what had caused my reaction, since it didn't start until after I had finished gardening. It wasn't until the third occurrence that I realized that the sumac was the common factor. Then I did some reading, and found a reference that said some people may have an allergic reaction after absorbing through their skin the oils contained in the leaves and downy stems of many Rhus species (not just Poison Sumac). So, it's not everybody that is affected, but anyone handling this plant for the first time should be cautious.