Toxicodendron is a genus of flowering plants in the sumac family, Anacardiaceae. It contains trees, shrubs and woody vines, including poison ivy, poison oak, and the lacquer tree. All members of the genus produce the skin-irritating oil urushiol, which can cause a severe allergic reaction. The generic name is derived from the Greek words τοξικός (toxikos), meaning "poison," and δένδρον (dendron), meaning "tree". The best known members of the genus in North America are poison ivy (T. radicans), practically ubiquitous throughout most of eastern North America, and western poison oak, similarly ubiquitous throughout much of the western part of the continent.
Toxicodendron radicans, commonly known as eastern poison ivy or poison ivy, is an allergenic flowering plant that occurs in Asia and eastern North America. The species is well known for causing urushiol-induced contact dermatitis, an itchy, irritating, and sometimes painful rash, in most people who touch it. The rash is caused by urushiol, a clear liquid compound in the plant's sap. The species is variable in its appearance and habit, and despite its common name, it is not a true ivy (Hedera), but rather a member of the cashew and pistachio family (Anacardiaceae). T. radicans is commonly eaten by many animals and the seeds are consumed by birds, but poison ivy is most often thought of as an unwelcome weed. It is a different species from western poison ivy, T. rydbergii, which has similar effects.
Sumac or sumach is any of about 35 species of flowering plants in the genus Rhus and related genera in the cashew family (Anacardiaceae). Sumacs grow in subtropical and temperate regions throughout every continent except Antarctica and South America. Sumac is used as a spice, as a dye, and in medicine.
Toxicodendron diversilobum, commonly named Pacific poison oak or western poison oak, is a woody vine or shrub in the sumac family, Anacardiaceae. It is widely distributed in western North America, inhabiting conifer and mixed broadleaf forests, woodlands, grasslands, and chaparral biomes. Peak flowering occurs in May. Like other members of the genus Toxicodendron, T. diversilobum causes itching and allergic rashes in most people after contact by touch or smoke inhalation. Despite its name, it is not closely related to oaks, nor is it a true tree.
Toxicodendron vernix, commonly known as poison sumac, or swamp-sumach, is a woody shrub or small tree growing to 9 metres (30 feet) tall. It was previously known as Rhus vernix. This plant is also known as thunderwood, particularly where it occurs in the southern United States. All parts of the plant contain a resin called urushiol that causes skin and mucous membrane irritation to humans. Urushiol is the same chemical that poison ivy is covered in. When the plant is burned, inhalation of the smoke may cause the rash to appear on the lining of the lungs, causing extreme pain and possibly fatal respiratory difficulty.
Urushiol-induced contact dermatitis is a type of allergic contact dermatitis caused by the oil urushiol found in various plants, most notably sumac family species of the genus Toxicodendron: poison ivy, poison oak, poison sumac, and the Chinese lacquer tree. The name is derived from the Japanese word for the sap of the Chinese lacquer tree, urushi. Other plants in the sumac family also contain urushiol, as do unrelated plants such as Ginkgo biloba.
Rhus typhina, the staghorn sumac, is a species of flowering plant in the family Anacardiaceae, native to eastern North America. It is primarily found in southeastern Canada, the northeastern and midwestern United States, and the Appalachian Mountains, but it is widely cultivated as an ornamental throughout the temperate world. It is an invasive species in some parts of the world.
Toxicodendron rydbergii, the western poison ivy or northern poison oak, is a species of Toxicodendron in the cashew family native to North America.
Toxicodendron pubescens, commonly known as Atlantic poison oak, is an upright shrub that can grow to 1 metre (3 feet) tall. Its leaves are 15 centimetres (6 inches) long, alternate, with three leaflets on each. The leaflets are usually hairy and are variable in size and shape, but most often resemble white oak leaves; they usually turn yellow or orange in autumn. The fruit is small, round, and yellowish or greenish. It is not closely related to true oaks.
Rhus ovata, commonly known as sugar bush or sugar sumac, is a shrub or small tree found growing in the canyons and slopes of the chaparral and related ecosystems in Southern California, Arizona, Baja California and Baja California Sur. It is a long lived-plant, up to 100 years, and has dense evergreen foliage that make it conspicuous. It is closely related to and hybridizes with the lemonade sumac.
Toxicodendron vernicifluum, also known by the common name Chinese lacquer tree, is an Asian tree species of genus Toxicodendron native to China and the Indian subcontinent, and cultivated in regions of China, Japan and Korea. Other common names include Japanese lacquer tree, Japanese sumac, and varnish tree. The trees are cultivated and tapped for their toxic sap, which is used as a highly durable lacquer to make Chinese, Japanese, and Korean lacquerware.
Rhus trilobata is a shrub in the sumac genus (Rhus) with the common names skunkbush sumac, sourberry, skunkbush, and three-leaf sumac. It is native to the western half of Canada and the Western United States, from the Great Plains to California and south through Arizona extending into northern Mexico. It can be found from deserts to mountain peaks up to about 7,000 feet (2,100 m) in elevation.
Rhus copallinum, the winged sumac, shining sumac, dwarf sumac or flameleaf sumac, is a species of flowering plant in the cashew family (Anacardiaceae) that is native to eastern North America. It is a deciduous tree growing to 3.5–5.5 metres (11–18 ft) tall and an equal spread with a rounded crown. A 5-year-old sapling will stand about 2.5 metres (8.2 ft).
Rhus glabra, the smooth sumac, is a species of sumac in the family Anacardiaceae, native to North America, from southern Quebec west to southern British Columbia in Canada, and south to northern Florida and Arizona in the United States and Tamaulipas in northeastern Mexico.
Poison ivy is a type of allergenic plant in the genus Toxicodendron native to Asia and North America. Formerly considered a single species, Toxicodendron radicans, poison ivies are now generally treated as a complex of three separate species: Toxicodendron radicans, Toxicodendron rydbergii, and Toxicodendron orientale. They are well known for causing urushiol-induced contact dermatitis, an itchy, irritating, and sometimes painful rash, in most people who touch them. The rash is caused by urushiol, a clear liquid compound in the plant's sap. They are variable in appearance and habit, and despite its common name, it is not a "true" ivy (Hedera), but rather a member of the cashew and pistachio family (Anacardiaceae). T. radicans is commonly eaten by many animals, and the seeds are consumed by birds, but poison ivy is most often thought of as an unwelcome weed.
Toxicodendron parviflorum commonly known as small-flowered poison sumac is a much-branched shrub bearing stalked leaves with three leaflets; the end leaflet is larger than the other two. The leaflets are obovate, with rounded tips, tapering bases and irregularly toothed margins. The flowers are tiny, yellowish and fragrant. The fruit is small, round and red when ripe. T. parviflorum is found in the Himalayas, from Kumaun to Bhutan, at altitudes of 700–1,100 metres (2,300–3,600 ft).
Toxicodendron succedaneum, the wax tree, Japanese Hazenoki tree (Sumac or wax tree), sơn in Vietnam or charão in Portuguese, is a flowering plant species in the genus Toxicodendron found in Asia, although it has been planted elsewhere, most notably Australia and New Zealand. It is a large shrub or tree, up to 8 m tall, somewhat similar to a sumac tree. Because of its beautiful autumn foliage, it has been planted outside Asia as an ornamental plant, often by gardeners who were apparently unaware of the dangers of allergic reactions. It is now officially classified as a noxious weed in Australia and New Zealand. It is one of the city tree symbols of Kurume, Fukuoka, Japan.
Rhus lanceolata, the prairie sumac, is a species of plant native to the south-western United States, and northern Mexico.
Aculops rhois, the poison ivy gall mite, is a species of Eriophyid mite found in North America. They form galls in poison ivy as well as other members of North American Toxicodendron and some species of Rhus.
