Poison or Guardian Oak?

Photo taken by Marc Gabor during our Animal Tracking Campout in Big Sur last Fall

Photo taken by Marc Gabor during our Animal Tracking Campout in Big Sur last Fall

All hail the mighty Guardian Oak, AKA Poison Oak! Strictly speaking, this California native plant  (Toxicodendron diversilobum) is not poisonous, but their powerful oils, called urushiol, do cause a very uncomfortable (and sometimes long lasting) allergic reaction in about 80% of the human population. Because Guardian Oak only irritates humans, the plant protects wild places, holding space for a myriad of other animals who rely on the plant for food and habitat – hence the eco-centered re-brand of “guardian”.

Various techniques have been used historically by Native and non-native Californians to build up tolerances to Guardian Oak: feeding the first spring leaves to small children, wrapping acorn bread with large leaves when baking, collecting pollen, eating honey from bees that feed on the flowers, drinking milk from goats that feed on the leaves.

The roots, which contain the most urushiol, are known to yield a particularly potent black dye used by some Indigenous Californians to richly darken baskets and textiles. Charcoal from the roots was/is sometimes rubbed on the skin and tapped in (stick-and-poke style) to create very long-lasting tattoos.

The name ‘urushiol’ comes from a relative, the Japanese Lacquer Tree (Toxicodendron vernicifluum), Urushi in Japanese. In Japan the Urushi-oils have been used for millennia to preserve wood for building, and many of the country’s oldest Shinto and Buddhist temples are protected by the oils of Guardian Oak’s relation – quite the guardian indeed.

Guardian Oak is not closely related to true Oaks; the name comes from the similar look of the leaves, which always grow in clusters of three, hence the helpful rhyme: “leaves of three, let them be!”.

Tell us about your encounters with this guardian. Any treatment or prevention methods that you just love? How about horror stories or positive encounters?