Tour Stop 7: Poison Ivy

Poison Ivy at LCNP.

“Leaves of three, let it be.” That old saying sums up the most recognizable thing about poison ivy: it has three leaflets. The middle leaflet is a little larger than the other two, but each measures 2 to 4 inches in length. The smooth leaves are a glossy or dull green, changing color to red in autumn. Where all three leaves come together at the stem, it is red like a stop sign warning you not to touch. There are also 2 other leaflets often, slightly down the stem from the ones with 3 leaflets.

Poison ivy can grow as a low, non-woody plant, an upright 3-foot-tall shrub, or a woody vine that attaches to a tree trunk and winds its way upward. Don’t touch this vine, but do examine it. You will see that there are aerial roots on all sides of the vine, making it look like a fuzzy rope. These aerial roots distinguish the poison ivy vine from some of the other common vines that you will see at The Lorraine Cherry Nature Preserve. The beautiful orange-flowered Trumpet Vine also has anchoring aerial roots, but only on one side, the side where they are needed next to the tree. These aerial roots are only for support of the vine, and do not generally damage the supporting tree. The Greenbriar Vine, which produces one leaf at a time climbs trees, but has thorns instead of aerial roots. The harmless and beautifully lush Virginia Creeper will also grow low on the ground or climb trees, but has leaves of 5 instead of leaves of 3.

During summer, poison ivy produces white berries that are enthusiastically eaten by birds, including the Downy Woodpecker. Birds don’t seem to be affected by the toxins in the plant.  

All parts of poison ivy are toxic to humans. In addition to “leaves of three, let it be,” you should also remember: “if it’s hairy, it’s scary!” and “berries white are a fright.” The rash that can result when those sensitive or allergic are exposed to poison ivy can be a nuisance. It is caused when the oils from the vine, its leaves, roots or its berries, come into contact with your skin. If you brush up against it, and you have a water bottle with you, immediately wash the area that brushed up against the vine. If you don’t, take a shower and clean the area with soap and water as soon as you get home to limit the area the oils may spread to after exposure.

Poison Ivy Detail

 

Poison Ivy

Poison Ivy is also, strangely, poisonous to itself. If it wraps around itself, it will burn its own leaves with its oils. It iis a native plant that the birds and animals love but, like mosquitos, it plays a role in keeping humans out of certain spaces so that other life can flourish.

It’s important that we all learn to identify it (in all its clever disguises) so that we can give this plant the space it needs, and keep ourselves and each other safe from its poison.