David Hammond wrote:When I was a Boy Scout, the only sumac I knew about was Poison Sumac, so the first time I saw this ingredient on a menu, I was intrigued.
There is, of course, a difference between the kind of sumac that grows in Chicago forest preserves and the spice that’s found in some Middle Eastern food. One may cause a severe allergic reaction and the other adds a slight citrus note.
The Mediterranean spice sumac is
Rhus coriaria, also known as Sicilian sumac or Tanner's sumac. Poison sumac is
Toxicodendron vernix or
Rhus vernix, and closely related to poison ivy (
Toxicodendron radicans, Rhus toxicodendron or
Rhus radicans).
Two North American species also to be found in the forest preserves, smooth sumac (
Rhus glabra) and staghorn sumac (
Rhus typhina), were used by Native Americans in cooking. I'm surprised the Boy Scouts didn't teach you to make "Indian lemonade" from the berries.
There are some 250 related
Rhus species, many of which are apt to cause allergic reactions, along with other plants in the family
Anacardiacea, such as mangoes, cashews and gingko. I am highly allergic to staghorn sumac -- to the extent that I'll react if I simply walk through woods where it's growing -- but don't seem to have any trouble ingesting the Middle Eastern spice, which is typically one of the components of the seasoning blend
za'atar, along with thyme and sesame seeds (among other variants).
I am not certain whether this difference has mostly to do with varying levels of allergens among the species or with the respective plant parts. (For example, what most people react to in poison ivy, et al., is urushiol, a component in the sap. Urushiol is present in mango peel but not the flesh, so people sensitive to it can eat ripe mangoes, so long as they avoid contact with the skin.)