Bay Area Hiker: Poisonous Plants
Poisonous Plants
(Nerium oleander), Windy Hill Open Space Preserve

(Xanthium strumarium), Jordan Pond, Garin Regional Park

California buckeye
California Buckeye
(Aesculus californica) pods, autumn, Meyers Ranch Trail, Garin Regional Park
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Poison oak
Poison Oak
(Toxicodendron diversilobum), autumn, Bear Gulch Trail, Wunderlich County Park
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Oak mistletoe
Oak mistletoe (Phoradendron villosum), Ridgeline Trail, Del Valle Regional Park
Blue witch nightshade
Blue witch nightshade (Solanum umbelliferum), spring, Sneath Lane Trail, Sweeney Ridge

White nightshade
White Nightshade (Solanum nodiflorum), Burleigh Murray Ranch State Park
Poison hemlock
Poison hemlock (Conium maculatum), spring, Abbotts Lagoon, Point Reyes National Seashore

Cotoneaster (Cotoneaster franchetii), winter, Phillips Loop Trail, Redwood Regional Park
Some poisonous plants seem to be warning you not to eat them (see cocklebur picture), while others present a less threatening front. It's never a good idea to eat something unknown, but if you know a plant is poisonous, you can avoid even handling that plant. In his excellent book Edible and Poisonous Plants of Northern California (order this book from, James Wiltens recounts the sad tale of an army of French troops who made the mistake of using oleander branches as skewers for cooking meat. He says 300 men were poisoned and some died. Don't mess with mother nature; learn about poisonous plants and stay away from them.