Don’t Touch Me: Plants to Avoid

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Weeds. Usually, they are just an annoying part of our summer life. Sometimes, like in the case of dandelions, they can rise above annoying and actually contribute to our well-being. Then, sometimes they can be the complete opposite and be downright dangerous to us and our pets, thus enter the world of noxious weeds.

Noxious weeds, by definition, are weeds that are considered harmful to the environment or animals, especially one that is the subject of regulations governing attempts to control it.

Most of them are spread by nature. Seeds are carried by the wind, water and wildlife. Humans and pets pick up seeds that stick in the tread of boots and shoes, on clothing and animal fur. Animals’ paws carry seeds near and far. Most noxious weeds have more than one method of propagation. Besides seeds, some send out rhizomes. Species such as knotweed can spread by seeds and fragmentation, just a piece of its root will grow a new plant.

Most noxious weeds were introduced to a region by humans for a certain purpose. Thus, what may be considered a noxious weed in one state or area may not be in another. The Department of Environmental Conservation or the local extension service can provide information on what plants are hazardous in your area.

There has been a lot of buzz lately about one certain plant that is particularly hazardous if people come into contact with it. The culprit is 14 feet tall, green, hairy, covered in toxic sap and is known as giant hogweed. This massive plant causes painful burns, scarring and possible blindness.

Hogweed is native to Asia but naturalists introduced the plant to this country in the 1900’s. Its size and enormous flowers made it desirable for ornamental planting. It remains small for 3 to 5 years and then gains enough energy from its roots to rocket in growth and produce early summer flowers that are one to two feet in diameter and 5-foot wide jagged leaves.

With no known disease or insect pests to control it, hogweed soon escaped to the wild and is becoming widespread. An average hogweed plant produces 20,000 seeds that can fall 30 feet from the plant and travel even further. As of date, it is found in Virginia, Maine, Massachusetts, Vermont, Connecticut, New York, Pennsylvania, North Carolina, Michigan, Illinois, Washington and Oregon.

So, what makes this plant so bad? The danger is in the sap, which is literally all over the plant. Once a person comes into contact with it, it causes severe burns when exposed to the ultraviolet light from the sun. For some, this can happen within 15 minutes of contact and for others it may take up to two days.

When the painful blisters subside, permanent scarring can remain. The more sap you come into contact with, the greater the damage. Once in your system, it makes your skin unable to protect itself from the sun. This reaction is known as phytophotodermatitis, the same condition that occurs when certain antibiotics makes you more sensitive to the sun. This sensitivity can last for up to six years and in the more severe cases it can cause blindness.

A recent incident involving a giant hogweed sent a 17-year old boy to the emergency room with second and third degree burns after he chopped down one of these plants as part of his summer landscaping job. Alex Childress of Spotsylvania, Virginia, didn’t notice anything was wrong until he went to take a shower the night after he chopped it down. He told PEOPLE magazine that he started rubbing his skin and huge chunks started falling off. He must now avoid the sun for six months.

Hogweed likes lots of light and moist soil but it is also found in partially shaded areas, along streams, river banks, roads, forests, fields, yards and basically anywhere! Two similar looking plants are often mistaken for it, cow parsnip and angelica. However, the plants can be differentiated; cow parsnip only grows to about 6 feet in height and angelica has compound leaves and smooth stems. Hogweed has white hairs and purple blotches on its stems.

If you do happen to come into contact with it, wash with soap and water as soon as possible and get to a doctor ASAP.

Although giant hogweed is the big bad boy of noxious plants, there are others that can also make you sick or just downright uncomfortable. Depending on a person’s system, some may have severe reactions to certain plants while others have mild reactions. They are also divided into various categories on how they affect a person.

Irritant Sap

Noxious plants that contain irritant sap include buttercup, clematis, daffodils, marsh marigolds, euphorbias, among others. Avoid the sap coming into contact with your skin.

Phototoxic Plants

These include hogweed, angelica, Bishop’s weed, celery, chervil, fennel, fig, gas plant, lime, masterwort, parsley, Queen Anne’s Lace, rue and others.

Prickly Plants

These plants have tiny irritating bristles and/or sharp serrated leaves. Some are prickly bear, cactus, hops, Ravenna grass, redtwig dogwood, stinging nettle and thistles.

Allergi Dermititis

These cause rashes and blistering and usually occurs once a person becomes sensitized to the plant. This list includes poison ivy, poison oak, poison sumac, ragweed, aster, balsam fir, black-eyed Susans, bleeding heart, castor bean, daisies, English ivy, feverfew, garlic, ginkgo, marigold, primrose, tomato, trumpet vine and tulip.

Plants Not to Inhale

Airborne pollen can cause allergic reactions as with ragweed, various grasses and conifers.

Plants Not to Eat

The rule of thumb here is not to eat anything unless you know beyond a shadow of a doubt what it is. There is a long list here, but some more prominent ones are lily of the valley (even the water in the vase it is in is toxic), hydrangeas, mountain laurel, rhododendrons, azaleas, yew and many others.

Some of these plants listed lend color to our gardens, provide food and also medicine for us. Some parts of different plants are noxious such as stems, leaves, roots, etc. while other parts of the same plant are not. The key to staying safe is to know your plants and when in doubt…don’t touch it!

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