Most boaters love hiking through the forests, valleys, and along river trails of the Pacific Northwest, and we are often reminded to “be bear aware,” but how many of us are “plant aware?” How many of us can identify the plants we should stay away from?

Unlike animals, plants can’t move or run away from danger. To protect themselves from preditors, many plants contain chemicals or poisons. Other forms of defense are structural, including tuff bark, thorns on branches, or spines on leaves. It often comes as a surprise that plants can sense changes in their surroundings and respond to light, gravity, temperature changes and yes, touch. Touch is where we come in; knowing what not to touch can save us a lot of grief. Accidently touching or brushing up against poisonous plants can bring some very unpleasant consequences.

There are untold numbers of plant species that cause humans harm. We will cover a few of the more common species found in the Pacific Northwest. Boaters may be familiar with some of these plants like poison ivy and poison oak, but may not be familiar with some of the more dangerous species like the Giant Hogweed. As boaters, we often go to remote locations and marine parks where many of these noxious plants are found.

Giant Hogweed

This hairy perennial is distinguished by its large size, growing to heights of 15-20 feet. It has stout dark reddish-purple spotted stems with white hairs. Leaves on the leaf stalks can be 5 feet in breadth and have a deep cut. Numerous small white flowers make up the broad, flat-topped flower clusters at the top of the stems. The flowers produce oval dry seeds marked with brown swollen resin canals. Saplings start out small, taking 3-5 years before beginning their rapid growth spurt.

This noxious weed is covered in toxic sap that causes painful burns, large blisters, scarring, and possibly even blindness. The sap contains toxic chemicals which makes your skin unable to protect itself from the sun. When the skin comes in contact with the sap, severe burns appear when the skin is exposed to UV light from the sun. Even when the painful blisters subside, permanent scarring can remain. The Wild Parsnip plant is in the same plant family and produces the same toxic sap, but doesn’t grow as tall; look for yellow flowers and grooved stems. If you come in contact with these plants, immediately wash the affected area with soap and water and contact your physician. You may be prescribed topical or oral steroids to reduce the severity. Be sure to cover the skin to protect it from sunlight for the next few days. When it’s blistered, wrap the skin with an ace bandage. Wearing protective clothing for the next few years helps reduce scarring.

Poison Ivy

This small plant or weed has three leaves to a stalk. Two of the leaves are attached to the stalk opposite each other, while the third leaf juts out in the center, perpendicular to the other two leaves. The three leaves create a triangle shape. An easy way to remember is to repeat the adage, “leaves of 3, let it be.” When we think about poison ivy, we assume shiny green leaves, but the leaves of this nasty plant turn all sorts of bright colors all year long, including red, yellow, and orange.

If our skin comes in contact with poison ivy, a rash develops; it’s the body’s reaction to the oil on the leaves, stem, and roots. The rash may start out slowly, looking like a bug bite or scratch at first, and may take a week before the full-blown rash appears. Once it spreads, itchy red bumps or small blisters appear on the skin, often in the shape of a straight line. Applying anti-itch gel or using Calamine lotion will help alleviate the itch. Don’t forget to wash any clothing that has come in contact with the plant.

Poison Oak

Similar to poison ivy, poison oak has leaves that come in groups of three. This plant can be very tricky to identify because it can take on the shape of other plants nearby. Its leaves may be serrated, round, or oak-like depending on what other foliage is around. Its leaves may be shiny or not, and have a red tinge or not. The plant may appear close to the ground, or more like a bush, or even a vine climbing a tree. Blooms on poison oak consist of small white flowers, which sometimes turn into greenish or tan berries.

Like poison ivy, the oil on leaves, stems, and roots of poison oak triggers the body’s immune system to produce a rash when the skin comes in contact with the plant. The rash usually appears between a half day and 3 days after contact. The irritation worsens as time goes on, developing into a red rash, with bumps that can turn into blisters. This nasty rash usually takes 3-4 weeks to resolve. Some people may have a severe allergic reaction and should seek medical attention. If your skin comes in contact with poison oak, wash with warm, soapy water as soon as possible. Use emollient cream to keep the skin from losing moisture; antihistamines can ease the itchiness but remember they can also make you drowsy.

Stinging Nettle

Nettles are perennial flowering plants that come in a variety of species. Plants grow 3-7 feet tall and have green leaves 1-6 inches long. The leaves are strongly serrated with a prominent point or tip at the end. The erect, wiry stem, as well as the leaves, are very hairy; these hairs can be non-stinging or stinging depending on the species. The plant grows in abundance in the Pacific Northwest.

Hollow stinging hairs of some species act like needles and inject histamine, serotonin, choline, and other chemicals that produce a burning, stinging sensation upon contact, followed by a rash. It’s best not to touch the affected area within the first 10 minutes of the sting, as touching can push the chemicals deeper into the skin. The rash appears as raised bumps or hives, which are light in color; the skin surrounding the hive may be red. Creams containing antihistamines or hydrocortisone can provide some relief and should be dabbed on, not rubbed on. A cool compress may also provide relief. People that have a serious allergic reaction to stinging nettles should seek medical attention. Normally, a stinging nettle rash disappears within 24 hours.

While all of these plants give us pause for concern, we can avoid their ill effects by identifying noxious plants and avoiding contact. We can take further precautions by wearing long pants, boots, long-sleeved shirts, a hat and gloves when hiking. Dogs should be bathed after returning from a hike if you suspect contact with noxious plants to prevent poison transferring to your skin.

The Pacific Northwest offers gorgeous scenery and numerous hiking opportunities, so have fun and “be plant aware.”

Lorena Landon
Co-Managing Editor
Waggoner Cruising Guide