Cross-Sensitization in Diverse Poisonous Members of the Sumac Family (Anacardiaceae)11FAMILY ANACARDIACEAE. The bark of these plants characteristically has canals which contain a milky-white sap that often dries (especially in the caustic members) into a black lacquer-like material on contact with the air. The canals connect with canals of the leaves, and usually with the flowers and fruits. The family falls into five quite distinctive tribes; the following key indicates some of the characteristics of each tribe:Tribe Dobineae: Perianth absent: carpel 1: leaves simple.Tribe Mangiferae: Perianth present: carpel 1 (or 5 and then not united); carpel (or carpels) not sunken into and united with the receptacle; leaves simple.Tribe Spondieae: Carpels 3 to 5, united. Carpels usually 4 to 5 (rarely more or only 3); usually all carpels fertile.Tribe Semecarpeae: Carpels usually 3, all but 1 not fertile. Base of fruit sunken into the receptacle; leaves usually simple.Tribe Rhoideae: Base of fruit not sunken into the receptacle; leaves usually compound.