Tuesday, July 26, 2016

Poison Ivy

The Blight of the Lower St. John River Valley

Poison Ivy 

In the lower St. John River Valley,  Poison Ivy  (Toxicodendron rydbergii) is common.  It prefers habitats that are rich, alluvial soil, rocky, sandy shores, and sometimes swampy woods and thickets.  In my area it is rich and lush.  Its leaves are always in 3s and often shiny.  The green can be anything from a light yellow green to a dark blue green.  It can be a low plant to a metre high.  It has very small whitish  or greenish flowers which grow in leaf axils in branching clusters.  The berries are yellowish green when unripe but turn whitish or grayish when dried.

Poison Ivy Showing Fruit
There are two species of poison ivy in New Brunswick, Toxicodendron rydbergii shown above and Toxicodendron radicans which is less common. T. radicans prefers more rocky, sandy shores.  It differs from T. rydgergii by its leaves being less toothed and it has aerial rootlets and likes to climb.  I have seen it climbing up trees and telephone poles.  Both species turn red in the fall.

Poison Ivy Berries

Poison Ivy is a seriously toxic plant.  It causes a severe skin irritation on contact.  It causes redness, itching, blistering and serum often oozes from the blisters.  I have had it a few times and can attest to the severe itching and irritation.  It is not uncommon for people to have to seek medical attention for treatment.  If the berries are eaten they can cause severe irritation to the digestive tract!  

In order to become affected by poison ivy, one's skin must actually come in contact with the plant.  If you are protected by clothing, you are probably not affected.  However, if your clothing has been in contact and then secondarily your skin comes in contact with the clothing, then you will also become affected.  The same goes for your dog or cat.  It they have walked through the poison ivy patch and then you pat them or brush against the affected fur, you will get the irritation.  

What do you do if you accidentally come in contact?  Washing thoroughly immediately after will usually prevent the irritation.  What if you are out on a hike and you have come in contact and there is no soap and water available?  I have heard that if you pick the touch-me-not plant (jewelweed) and rub the crushed plant on the affected skin, that will prevent the irritation.  I have tried this and it worked.  However, a thorough washing is a better preventative measure.

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