poison ivy and poison oak Here is a link to some other poisonous poisonous plants_
These poisonous plants, members of the cashew family, consist of woody vines and coarse shrubs that arise from extensive underground stems or rhizomes. Poison ivy, native to the eastern U.S., is found commonly along roads, growing on trees and walls. The woody vines have alternate, trifoliate leaves (hence the common cautionary saying: "if 3 leaves, let it be") with a smooth (glossy) surface with few or no lobes/dentatation, aerial roots, and white berries. Another species, poison oak, native chiefly to the south eastern U.S., has trifoliate leaves with each leaflet having 3-7 lobes. This plant often grows 2-6 feet tall. The species poison sumac, native to the eastern U.S., is a shrub that can grow to 21 feet tall with leaves that have 7-13 leaflets and light, yellow-gray berries in the autumn. These poisonous plants flower in spring and sometimes again in late summer to early autumn.This is a link