Every plant and animal possess unique characteristics that can be used to identify it’s species or name. While specifying the name of every plant on your property is usually not necessary, sometimes weeds can become an issue if they are dangerous, out of control, or simply not welcome. Correct weed identification is important in developing effective methods of control and management.
All species have a variety of names. The first name given is typically a scientific name in Latin that describes the genus and species of a particular weed. The second name in plain English, or the common name, is typically easier to pronounce but can be less precise or specific than a scientific name. For an example, you may have heard of common lambsquarters, which is scientifically known as Chenopodium album. The good news is that there is not always a reason for a homeowner or layperson to have to know or use the scientific name—for most of our weed identification purposes, an accurate common name will do just fine.
If you happen upon a new weed or one you aren’t familiar with, there are several things you can look at to help you identify it. First, I like to consider general growing environment. Is this a weed a recurring perennial weed that comes out at a specific time each year? What time of year do we see it grow, and when do we typically see it go dormant? Is this an annual weed that only grows one season before dying? If it’s an annual, when do we see it emerge and grow? Other environmental things may be whether this weed grows in full sun, well drained areas or shaded, water-holding spaces. Anything you can identify about how and where the weed grows is useful to identifying it.
In addition to environmental conditions, I like to look at the plant itself to help identify key characteristics of it. I generally start with the leaves—identify how they are arranged on the stem. Are they opposite one another or staggered at different intervals? Are they simple (one leaf) or compound (multiple leaves) and what shape are they? After taking a look at the leaves, move on to the flowers. What color, shape, and size are they? How are they arranged—single flowers or groups of flowers on one stem? Are there seeds, fruits, or other identifying things like thorns? What about how the weed is growing? Is it close to the ground and sprawling, or more erect in nature? The more identifying characteristics that you see and can identify, the closer you will get to a correct ID on the weed.
Once you’ve done some homework, there are a few things you can do to help identify the weed. You can contact us at the Extension office and we are happy to come to your property at no charge to help identify what you might be dealing with. There are also a variety of great weed identification resources such as reference books, dichotomous keys, or interactive keys. My personal favorite is the Weed ID Guide from the University of Missouri Division of Plant Sciences. Once you have an accurate weed identification, you can accurately determine what steps you need to take for effective control (and Extension can help with that too!).
