Poison Oak: The Trail Less Traveled

When taking to the many scenic trails Agoura Hills has to offer, it’s important to be aware of your surroundings. Natural hazards like rattle snakes, ticks and toxic plants abound, but as long as you are armed with the right information, you will safely navigate around true dangers.      

So here is some information on one of the wiliest and most hazardous species of plant you may come across while hiking in Agoura: Poison oak.

Poison oak, Toxicodendron diversilobum, is an amazingly adaptive plant that grows in a number of different life forms-as a vine, low growing bush, or shrub. Its adaptations will even go so far as to change its leaf shape to better access its nearby resources. But there are some identifying characteristics that never change. Poison oak’s leaves are pinnately compound, having leaflets of three. Hence, the old adage of “Leaves of three, let it be.”

The leaves are generally lobed and leathery and often this plant is confused with a berry vine. But unlike berries, poison oak does not have thorns. During spring and summer the leaves are green and shiny, turning into a brilliant red or yellow in fall. Poison oak is deciduous and bare in the winter, making it difficult to identify. The flowers of this plant are small and inconspicuous, blooming from April through May.

The berries are white and toxic.

All parts of this plant, including bare stems, can cause some type of skin irritation.  At least fifty percent of the human population in North America has an allergic reaction to this plant when direct contact is made. The allergy manifests in a rash that can be red, swelling, itchy and blistering. People who are extremely sensitive may acquire the rash from secondary contact, such as touching clothing, tools, or animals that have come in direct contact with poison oak.

But do not fear! Preventatives and remedies for poison oak exist. One of the most effective and easily found preventatives is mugwort (Artemesia douglasiana), which often grows near poison oak. Prior to contact with poison oak, take the leaves of mugwort and crush them so that they are moist. Rub these moist leaves on any exposed skin. One chemical component in mugwort renders the toxic chemical, urushiol, found in poison oak, harmless. I have found this to work very effectively. Every part of poison oak contains urushiol. This irritant is also found in poison sumac, poison ivy and the lacquer plant of Asia.  

Other cures for poison oak include a poultice made from the root of Chlorogalum pomeridian or soap root. Early settlers used salts such as baking powder to ease their rashes. Another easy remedy is a soap distributed by Burt’s Bees. This soap is most effective after exposure to poison oak, ivy, and sumac. 

There are several more invasive treatments for a poison oak rash such as cortisone creams or Technu, but I only recommend these for extreme cases when nothing else will work.

Beyond being a hazard, poison oak has many practical uses.  Historically, tinctures made from the plant’s juice were used to cure minor skin ailments and for the removal of warts. These tinctures were also known as a cure for ringworm. If applied directly after a rattle snake bite, the juice is said to counteract the venom.           

Over the years I have had many encounters with poison oak; some have resulted in a flaming rash while others have produced only an admiration for the beauty and versatility of this plant. Rather than a nuisance, I have come to think of this species as a teacher. I have had to become more agile in my walking, and my awareness has increased tenfold in order to avoid it.  But most of all, I have learned not to fear it, which often allows me to take the trail less traveled.