This month's Nature Notes was written by Bria Fleming. Bria is responsible for harvesting and processing native plant seeds for our Kankakee Sands Restoration in Morocco, Indiana.
During the holidays, we spend time with friends and family. This holiday season, why not spend some time with another family: grasses (family name Poaceae)? This is a great time of year to study grasses, since the weather has turned colder and the landscape has turned browner and there are no more showy wildflowers to divert our attention. Most of what we see in the prairie now are the skeletons of tall thick grass-like plants, ranging in color from pale straw to deep copper.
Grasses have a huge variety of human uses. There are species we eat (corn, wheat) and build with (bamboo), and there are hundreds of varieties native to our area that have been here all along, providing food and habitat for primitive humans and wildlife. Grasses grow in every environment imaginable, from the top of dry sand dunes to the cracks in your driveway to the edges of lakes and rivers.
Sharing the landscape with grasses are two more families—sedges and rushes. Take a look at the three photos. The plants shown all look like grasses but in fact there are three families represented: grasses (Poaceae – formerly Gramineae), rushes (Juncaceae) and sedges (Cyperaceae).
Many of the individual plants that make up the grass, rush and sedge families look very similar to each other. We see long narrow stems and leaves, and we’re tempted to identify the plant as a grass. Not so fast! It could be a sedge or a rush. There are easy ways of telling which type of grass-like plant you’re looking at. The truth is in the stem, which is useful because at this point in the year there usually aren’t any leaves left. The stem is quite persistent throughout the year and can be found and examined at any time (unless covered with snow of course).
This holiday season, between meals or football games, take a walk outside and look around a bit. You can go anywhere; a road-side or ditch, the woods, a pond or stream, or your own yard. If you have them, you can bring a scissors and/or a magnifying glass. Find a plant that looks like a grass. The bigger the better for your first one, as it will be easier to see the small parts. Once you’ve found your plant, grab the stem with your bare fingers and try to roll it around between your fingers. If the stem won’t roll easily, take a closer look. Is the stem triangular in shape? If so, congratulations! You’ve found a member of the sedge family. A good way to double-check this is to look straight down at the plant from above. If it’s three-sided, you’ll see leaves extending from each of the three sides.
If the stem is round, will roll easily between your fingers, and has leaves extending from only one or two sides, you can narrow it down a little further to a grass or a rush. There are a couple good ways to tell the difference between the two. The simplest one, again, involves the stem. Look closely up and down the length of the plant. Do you see noticeable joints? If so, you’ve found a grass! If you’re not sure, cut the stem and try to look inside. If the stem is hollow, your grass identification is confirmed.
Last but not least, perhaps you’ve found a grass-like plant with a round stem but no joints. At this point, you suspect that it’s a member of the rush family. The way to confirm this is to cut the stem and try to look inside. If the stem is not hollow but in fact filled with a spongy-looking substance, chances are you’ve found a rush!
While you almost never hear the word “always” when it comes to plant identification, these are a few reliable ways to begin your search. If you’re interested in a more in-depth discussion of these interesting and beautiful plants, check out the great little book How to Identify Grasses and Grass-Like Plants by H.D. Harrington. If you’re interested in grasses specifically, pick up Agnes Chase’s First Book of Grasses. To see native grasses, rushes and sedges in their natural habitat, stop by Kankakee Sands any time of the year and explore!
Stay tuned…next month’s Nature Notes will feature one of our favorite grasses… prairie dropseed.