How-to: Identify common poisonous plants
By CG Lifestyles & People Editor Neal Patten
This summer if you have been out hiking you have probably narrowly brushed past poisonous plants without even knowing it. Not straying from the designated trails in state parks and national forests helps ensure that you are safe from encountering irritating foliage. If you are more adventurous, however, well-worn paths are not likely to interest you as much as forging your own way through the woods. If that is the case, then being intimately familiar with dangerous greens will go a long way keeping a worry-free walkabout from turning into a sore siesta.
For this week’s how-to, I will show you how to identify five common plant pests to keep your explorations safe and enjoyable.
1. Poison Ivy
The old adage “leaves grouped in three, let it be” is a useful start for identifying Poison Ivy. However, that is not a guarantee as many wild plants grow with this pattern. Poison Ivy is a vine that often wraps around trees and fences. The groups of three leaves alternate along the stem. The middle leaf will be larger than the two side leaves. The lower two leaves will be a little lower on the stem than the top leaf and will originate from the same point. Finally, while leaf shapes vary – the leaves will never have serrations or ‘teeth.’
Poison Ivy. Courtesy of about.com
Only the leftmost leaf structure represents Poison Ivy. Image courtesy of electricant.net
2. Poison Oak
Poison Ivy most often grows as an individual stalk or vine, with a shrub being less common. The opposite is true for Poison Oak, which most often grows as a shrub and less commonly as a vine. Poison Oak leaves have lobes. Although not always pronounced, these lobes are key in identifying the plant. The leaves are typically 6 inches in length. The stems are grey-brown in color and covered in tiny hairs. During summer, the leaves are somewhere between yellow-green and pink. As a whole, the shrub won’t be higher than three feet.
Poison Oak. Courtesy of about.com
Look for the lobes. Image courtesy of wikihow.com
3. Poison Sumac
Poison Sumac, although often mentioned among the poison triumvirate, is actually (thankfully) not that common. It is only found in wetlands, with its roots growing in water. The first thing you will notice is that the stem is red. It is not hairy. You will find seven to nine leaves per stem. While Poison Ivy is a vine and Oak a shrub – Sumac is a tree. The trifecta of poisonous pests mentioned above all release the oil urushiol, an allergen, which causes rashes on contact.
Poison Sumac. Courtesy of comprehensivepediatrics.com
4. Wild Parsnip
This one is easy. If you know what Queen Anne’s Lace looks like, just paint it yellow and you are looking at wild parsnip. This plant grows off of a tall, deeply grooved stem. Unlike Poison Oak, Sumac and Ivy which all share similarities with other plants and could be confusing to identify, the yellow flowered head of Wild Parsnip is unmistakable. The sap of this plant, when in contact with skin, is activated by sunlight. It can cause blisters that continue to spread the longer they are exposed to the sun. This can be problematic if you are on a long hike without anything to cover-up the contact point.
Wild Parsnip. Courtesy of ipm.iastate.edu
5. Stinging Nettle
This plant has sharply serrated heart-shaped leaves. It generally grows between three and a half to six and a half feet tall, always upright. They favor moist soil and therefore are most often found along the edges of forests, water bodies and roads. Flowers grow in pairs of two up the stem, originating from the same point. The veins on the leaves are sunken. It is notable for its hair-like needles – these inject histamines into the skin, causing inflammation.
Stinging Nettle. Courtesy of nettle-tea.net
These five nuisances are sure to ruin the perfect summer day. So be smart, be vigilant and be safe. Happy hiking!
