Poison Sumac and Oak

Poison Sumac, Rhus vernix, of the eastern United States, is a shrub or small tree of the cashew family, Anacardiaceae. It grows to 6 m (20 ft) or more in height and has a smooth, gray, black-speckled bark. Its leaves divided into 7 to 13 smooth-margined leaflets, are from 15 to 38 cm (6 to 15 in) long and have bright red stalks.

The small, greenish white or yellowish green flowers are borne in drooping clusters on purplish stalks, followed by hanging clusters of small, grayish white berrylike drupes. The poison, considered more toxic than that of poison ivy, can cause serious skin reactions.

Poison Oak

The name poison oak is often applied to the shrub like forms of poison ivy and to at least to similar plants that are usually considered separate species of the cashew family, Anacardiaceae. The poison oak of the southeastern United States. Rhus quercifolia, has leaves divided into three hairy leaflets that generally have three to seven distinct lobes. The poison oak of U.S. pacific coast, R. diversiloba, is a shrubby or sometimes climbing plant; its three-leaflets leaves are toothed or lobes and are hairless. Both species contain poisonous substances that are believed to identical or closely related to that found in poison ivy.