Toxicodendron diversilobum (Torr. & A. Gray) Greene
poison oak (Pacific poison oak)
Anacardiaceae (Sumac family)

Introduction to Vascular Plants


© Adolf Ceska     (Photo ID #11274)


E-Flora BC Static Map

Distribution of Toxicodendron diversilobum
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Species Information

Deciduous shrub 1-2 m tall or woody climbing vine up to 15 m tall, glabrous to hairy, exuding milky juice when cut.
Leaflets 3-5, rounded, obtuse or sometimes sharp-pointed at the tips, 3-7 cm long, turning scarlet in autumn.
Inflorescence in loose, axillary, often reflexed panicles; flowers bisexual or unisexual, 1-2 mm long, yellowish-green; stamens exserted.
Berrylike drupes, 5 mm long, white, glabrous.
Many people develop an itching or burning rash after contacting this plant because of its slightly volatile oil.

SourceThe Illustrated Flora of British Columbia


If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

Habitat and Range

Dry to mesic rocky slopes (often climbing trees) in the lowland zone; rare in SW BC, known from SE Vancouver Island, the Gulf Islands and Howe Sound; S to MX.

SourceThe Illustrated Flora of British Columbia


Synonyms and Alternate Names:
Rhus diversiloba Torr. & A. Gray
Toxicodendron radicans subsp. diversilobum (Torr. & A. Gray) Thorne