I was recently given a recipe for a Turkish-style flatbread whose meat-based topping includes a few tablespoons of "Turkish Sumac Powder". Trouble is in my youth I was identified as having a sumac contact allergy and strongly advised to avoid touching the plant. Though many years have passed, I'm understandably reluctant to put it in my mouth. Is there a reasonable substitute? I was told it had a citrus flavor, but I'm guessing that lemon zest might be a bit too characteristic. Another person told me that Turkish sumac was not the same as the sumac that grows here in North America and that I needn't worry. I'm a tad dubious to check this out on myself. Ideas?