It’s botany time!
Today I’m going to continue talking about grasses (Poaceae).
If you recall from our last botany time, grass stems are hollow except for solid nodes that appear at regular intervals. These solid nodes are key to the survival of the grasses. Consider our front lawns…why can we mow our grassy lawns everyday without the grass dying? Now, think about what would happen if you had a lawn of roses, daisies, or lettuce and you mowed it every day? Many plants initiate growth from something called apical meristems that are located at the tips of stems so if we chop them off, it takes awhile for growth to initiate again (this is a bit of a simplified explanation). In grasses, however, the points where growth is initiated is at the solid nodes, new leaves and stem are created and pushed above from this node. This means when we cut off the top of a grass plant, the actively growing node is saved from damage and can continue growing away.
Pretty cool, eh? This ability allows grass to define ecosystems such as the Dakota National Grasslands, where ungulates like pronghorn antelope can eat away at grasses all day without wiping out the plants. To humans, grasses are also one of the most important plant families. The majority of the food we eat comes from a grass species. Think about rice, wheat, rye, corn, barley, oats, sugar cane, bamboo etc. Without these plants, much of the world would starve and die. Fortunately, grasses are typically wind pollinated, so even when all the bees die out from colony collapse disorder, even though we won’t have many delicious fruits, we’ll at least have grains.