Common name: poison oak
Scientific name: Toxicodendron diversilobum
Native American name: K’wan’-tee-tr’vt (Tolowa Dee-ni’)
Plant family: Anacardiaceae
T. diversilobum can grow as either a shrub or climbing vine. As a shrub it can grow from 1 ft to 9 or more feet in height. Vines vary between 10-30 feet in length. T. diversilobum features leaflets; each leaf features three pinnate leaflets, each between 3-7 cm and oval in shape. T. diversilobum leaves can resemble oak leaves, and as they share habitat with oaks, it is important to note this similarity. Leaves are deciduous, and change color from green and greenish-red in the spring and summer to dark red in the fall. Male and female T. diversilobum flowers occur separately. Furthermore, each individual has one sex of flower present. Therefore, T. diversilobum cannot self-fertilize. Flowers are inflorescent, white and grow from leaf axils, and range from shades of white, green and yellow in color. They bloom in the spring. T. diversilobum fruit are small white drupes, which are inedible to humans but are consumed by some birds and rodents. These fruit bear in the summer and fall. T. diversilobum vines spread themselves via roots and by working their stems into gaps. Shrubs spread by rhizome activity. Seeds are dispersed by birds. Shoots can be used to propogate.
T. diversilobum features a compound urushiol. Urushiol is an oily toxin, which can cause a range of allergic reactions upon skin contact.,  Contact with any part of the plant can result in a reaction, as all parts contain the toxin.,  Burning of the plant poses a special threat, as inhalation of urushiol can be deadly. , 
Habitat and Range: T. diversilobum grows in a wide variety of climates and soil types. It grows in elevations less than 5,500 ft. It is moderately shade tolerant. T. diversilobum can be found flourishing in a variety of woodland and riparian habitats, as well as in mountainous habitat. It also grows well on stream banks and in thicket. Its adaptability and tolerance for varied habitat is evidenced by its status as the most abundant shrub in California. However, T. diversilobum does require moist soil to thrive. T. diversilobum is found throughout the Northwest, from British Columbia to Southern California.. 
Historical and Contemporary Uses:
T. diversilobum had a variety of uses in the pre-European contact Pacific Northwest. Its branches were used, and still may be used as a basket-making material throughout central and southern California by a variety of tribes.
 Bommelyn, Loren Me’-lash-ne. Taa-laa-wa Dee-ni’ Wee-ya’; Formerly published as Now You’re Speaking-Tolowa The Deeni people, their language.2nd Edition, 2006
 Plants For a Future Database. Plant Profile Rhus diversiloba – Torr.&A.Gray. Accessed via http://www.pfaf.org/user/Plant.aspx?LatinName=Rhus+diversiloba
 Forest Service Plant Database. Accessed via http://www.fs.fed.us/database/feis/plants/vine/toxdiv/all.html
 University of Washington’s Burke Museum of Natural History and Culture. Herbarium Database. Accessed via http://biology.burke.washington.edu/herbarium/imagecollection.php?Genus=Toxicodendron&Species=diversilobum
 University of Texas at Austin Larry Bird Johnson Wildflower Center. Accessed via http://www.wildflower.org/plants/result.php?id_plant=TODI (
 United States Department of Agriculture Natural Resources Conservation Service Database. Plant Profile for Toxicodendron diversilobum. Accessed via http://plants.usda.gov/java/profile?symbol=TODI
 UC Berkeley, Cal Photo Database. Accessed via http://calphotos.berkeley.edu/cgi/img_query?query_src=photos_index&where-taxon=Toxicodendron+diversilobum
 University of Michigan-Dearborn Native American Ethnobotany Database. Accessed via http://herb.umd.umich.edu/herb/search.pl query: Toxicodendron diversilobum.