Discover the remarkable world found on a blade of grass: Nature News
Many of the flowers in my garden are flowering or about to flower. But did you know that many of our native (and non-native) grasses are also beginning to flower? This isn’t so great for those of us with pollen allergies, but if you can take the time to really look, you will discover a remarkable world on a blade of grass.
Grasses are flowering plants, like the zinnias in your garden or the red maples down in the swamps. They evolved relatively recently, around the time the dinosaurs disappeared — about 66 million years ago. They are closely related to orchids, but instead of using showy flowers to attract pollinators, the grass strategy is to take advantage of the wind. By doing this, they avoid putting energy into making those flowers and instead develop bare-bones structures for releasing (the male parts) and receiving (the female parts) pollen.
The grass flower is called a spikelet. Grass spikelets, like many typical flowers, are held in arrangements called inflorescences. That spike held on the top of a blade of grass is an inflorescence. That beautiful, delicate spray that can erupt from a blade of grass is also an inflorescence. If you get into the habit of looking at grasses a little more carefully, you will find some in bloom and will be able to see the male (anthers) and female (stigma) reproductive parts (you’ll need good eyesight or a hand lens/camera). The anthers are dangly, often colorful, tiny flowers, while the stigma looks like a feathery moth antenna (Erin Garrett, Illinois Extension). The anther releases the pollen to the wind, and the stigma receives it.
The only grass I can identify with any certainty is Timothy hay (Phleum pratense). While it isn’t native, I really love this grass. Timothy hay came over from Europe and is now widespread across North America. It gets its name from a Maryland farmer, Timothy Hanson, who is believed to be the first to grow and sell this grass (previously known as Herd grass after John Herd, who discovered it growing in the wilds of New Hampshire in 1711).
One tool to help identify grasses is to look at the structure of the spikelet. As mentioned previously, grasses have individual flowers called spikelets. In the case of Timothy hay, a closer look lets us see that each spikelet has two projections (called awns), sort of like little horns, a distinguishing feature of Timothy hay. Timothy hay also has very tightly packed spikelets, so the resulting inflorescence is straight and columnar with an almost velvety appearance. This is the quintessential grass stem we all plucked and chewed on as kids.
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I have found at least six or seven different types of grass growing in the field behind my house. One of the benefits of spending time looking more carefully at our grassy neighbors is what else you might see. While photographing some of the grasses that grow in my backyard, I discovered dozens of wee insects hanging out on the inflorescences. Some insects actually eat the pollen from the inflorescences, others use them to perch or hide. Looking for flowering grasses is just one more way to enjoy the bounty of summer.
Susan Pike, a researcher and an environmental sciences and biology teacher at Dover High School, welcomes your ideas for future column topics. Send your photos and observations to [email protected]. Read more of her Nature News columns at Seacoastonline.com and pikes-hikes.com, and follow her on Instagram @pikeshikes.
This article originally appeared on Portsmouth Herald: Discover the remarkable world found on a blade of grass: Nature News
