Search results
Results from the WOW.Com Content Network
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: T. radicans , T. rydbergii , and T. orientale .
Toxicodendron radicans, commonly known as eastern poison ivy [3] or poison ivy, is a species of allergenic flowering plant. It has numerous subtaxons and forms both vines and shrubs. It has numerous subtaxons and forms both vines and shrubs.
Poison oak is not an oak (Quercus, family Fagaceae), but this common name comes from the leaves' resemblance to white oak (Quercus alba) leaves, while poison ivy is not an ivy (Hedera, family Araliaceae), but has a superficially similar growth form. Technically, the plants do not contain a poison; they contain a potent allergen.
Urushiol is an oleoresin contained within the sap of poison ivy and related plants, and after injury to the plant, or late in the fall, the sap leaks to the surface of the plant, where under certain temperature and humidity conditions the urushiol becomes a blackish lacquer after being in contact with oxygen.
Urushiol-induced contact dermatitis (also called Toxicodendron dermatitis or Rhus 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. [1]
Unlike Toxicodendron radicans (eastern poison ivy), which often appears as a trailing or climbing vine, T. rydbergii is a shrub that can grow to 1 m (3 ft) tall, rarely up to 3 m (10 ft). The leaves are trifoliate and alternate. The leaflets are variable in size and shape, and are usually 15 cm (6 in) long, turning yellow or orange in autumn.
The differences in toxicity in poison ivy, poison oak, and poison sumac are due to differences in the side chains of the chemicals in these plants. In general, poison ivy has a C 15 side chain, poison oak has a C 17 side chain and poison sumac has a C 13 side chain. The dermatitis shows itself in painful and long continued swellings and ...
Toxicodendron orientale (Asian poison ivy) is an East Asian flowering plant in the genus Toxicodendron. It is a poison ivy , which can cause urushiol-induced contact dermatitis . Description