Toxicodendron radicans (syn. Rhus toxicodendron, Rhus radicans; Poison ivy) is a plant in the family Anacardiaceae. The name is sometimes spelled \"Poison-ivy\" in an attempt to indicate that the plant is not a true Ivy (Hedera). It is a woody vine that is well known for its ability to produce urushiol, a skin irritant that causes an itching rash for most people, technically known as urushiol-induced contact dermatitis.
For the trail, see Virginia Creeper Trail. For the Grant-Lee Phillips album, see Virginia Creeper (album).
Species: P. quinquefolia
Virginia creeper or five-leaved ivy (Parthenocissus quinquefolia) is a woody vine native to eastern and central North America, in southeastern Canada, the eastern and central United States, eastern Mexico, and Guatemala, west as far as Manitoba, South Dakota, Utah and Texas.
Black cohosh is a smooth (glabrous), herbaceous perennial plant that produces large, compound leaves from an underground rhizome, reaching a height of 0.25-0.6 m (7-18 in). The basal leaves are up to 1 m (39 in) long and broad, forming repeated sets of three leaflets (tripinnately compound) having a coarsely toothed margin. The flowers are produced in late spring and early summer on a tall stem, 0.75-2.5 m (2??8 ft) tall, forming racemes up to 50 cm (20 in) long. The flowers have no petals or sepals, only a tight cluster of 55-110 white stamens 5-10 mm long surrounding the white stigma. The flowers have a distinctly sweet, fetid smell that attracts flies, gnats, and beetles. The fruit is a dry follicle 5-10 mm long, with one carpel, containing several seeds.
The species has a history of taxonomic uncertainty dating back to Carl Linnaeus who, after some earlier revisions, had eventually placed it into the genus, Actaea, based on morphological characteristics of the inflorescence and seeds. This designation was later revised by Thomas Nuttall reclassifying the species to the genus, Cimicifuga, based solely on the dry follicles produced by black cohosh that are typical of species in Cimicifuga. However, recent additional data from morphological and gene phylogeny analyses demonstrate that black cohosh is more closely related to species of the genus Actaea than to other Cimicifuga species, prompting the revision to Actaea racemosa as originally proposed by Linnaeus. Blue cohosh (Caulophyllum thalictroides), despite its similar common name, is a plant of another genus.