This month's Nature Notes was written by Alyssa Nyberg, Nursery Manager at Kankakee Sands.
Grasses are one of those overlooked, unappreciated wonders of the world. Grasses are all around us. They inhabit frigid mountain tops, arid deserts and tidal marshes. Grasses can even create dense forests, as in the case of bamboo (which is actually a grass). They are the primary vegetation of the prairies, plains and savannas. In the prairies and savannas of Northwest Indiana and Northeast Illinois, our native grasses include little bluestem, indian grass, porcupine grass, june grass, tickle grass, witch grass, switch grass, prairie dropseed, sand reed, three awn grass and purple love grass. You may be familiar with the lawn and landscaping grass species fescue or Kentucky bluegrass. Though lovely and green, these grass species are introduced from Europe and not native to our area. Would you believe that in our Illinois and Indiana area, there are over 200 grass species? Across the United States there are 1,500 grass species greening up our country at this very moment.
Grasses are amazing in that they come in all shapes and sizes. Some are less than a foot tall, while others are over 100 feet tall. Some species grow only in a small clump, others can spread and overtake acres of land. Although there are over 8,000 grass species in the world, they all share several basic characteristics. The roots of grasses are always fibrous. Grasses have round or flattened culms/stems which are often hollow. Along the stem there are solid joints from which the leaves arise. Leaves are typically long and linear with parallel veins. Grasses have miniscule flowers which lack showy petals and are wind pollinated. Each flower produces just one seed. There are often multiple flowers per plant and thus multiple seeds per plant. The grass flowers, because of their small size, are rarely used to identify the grass species. Instead, botanists look at the leaves and the arrangement of bracts which protect the tiny, fragile flowers.
Grasses are absolutely remarkable; they take sunlight and make it edible. Here’s how: sunlight shines down on the earth, the sunlight is captured by the grass blades and converted to plant energy which the plants use to grow and spread. The world’s herbivores (voles, mice, sheep, cows, horses, deer, elk, moose, bison, etc.) dine on the grass blades and seeds. Once in the belly of the herbivore, the grass is digested and converted to meat, which feeds the world’s carnivores. Think about what you have eaten today; likely you have a grass species to thank for your most recent meal. Rice, maize, oats, barley, wheat and rye are all members of the grass family. Grass species are the number one food source for humans and animals alike.
Below the ground grasses are also vitally important. Grasses stitch the soil together with their zillions of fibrous roots and hold the soil in place, preventing soil erosion. Many grass species have roots which grow to a depth of more than 6 feet below the ground. Additionally, all grasses, whether annual or perennial, experience some root die-back each year. As the roots decompose the soil becomes organically rich in carbon. Historically it was the fertile prairie soils, a result of the decomposition of prairie grass roots, which were prized and plowed for agriculture.
This past winter, I decided to see if I could beat the winter doldrums by reading up on those glorious green grasses, which it turns out, are notoriously difficult to tell apart. Each reference book cautioned “trying to identify grasses will make you pull your hair out.” Despite the warning, I spent several weeks looking at dried grass specimens under a microscope and working through plant keys to try to differentiate grass species. Fortunately, I do have some hair left, but unfortunately, I cannot identify all the grasses of our area with great confidence. However, I will say that I have developed a deep and profound respect for the grass family.
So, three cheers for grasses! And by the way, have you hugged a grass today? If not, head on out to the prairies and savannas of Kankakee Sands where you will find plenty of glorious, green grasses of all shapes and sizes, ripe for hugging and appreciating.