UC IPM Online UC ANR home page UC IPM home page

UC IPM Home

Search

SKIP navigation

Home & garden
Agriculture
Natural environments
Exotic & invasive

Weather data & products
Degree-days
Interactive tools & models

Natural enemies
Weeds

Publications & more
Workshops and events
Training programs
Pesticide information

Grants programs
Funded-project results


 

How to Manage Pests

Identification: Weed Photo Gallery

Pacific poison-oak

Scientific name: Toxicodendron diversilobum (Sumac Family: Anacardiaceae)

Life stages of Pacific poison-oak top left picture bottom left picture right picture

Click on image to enlarge

DESCRIPTION:
Pacific poison-oak is a broadleaf perennial vine or shrub, sometimes treelike in form. It is known for its milky, poisonous oil that can cause a severe skin rash. Cotyledons (seed leaves) are egg-shaped to oblong, short stalked and often slightly glossy. First leaves are opposite to one another on the stem and consist of three leaflets. The terminal leaflet is lance-shaped and much longer than the lateral football shaped leaves. The leaves turn bright red in the autumn. It is particularly troublesome in the dry sandy soils of the foothills and dry-farmed mountain orchards. It reproduces from underground stems and from seed.

See UC IPM's Poison Oak Pest Note for more information.

Broadleaf ID illustration.


Statewide IPM Program, Agriculture and Natural Resources, University of California
All contents copyright © 2008 The Regents of the University of California. All rights reserved.

For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See How to manage pests, or in the U.S., contact your local Cooperative Extension office for assistance. /PMG/WEEDS/pacific_poisonoak.html revised: November 17, 2008. Contact webmaster.