A graminoid is a grass, or grass-like plant. The leaves are typically blade-shaped, and the flowers are plain by most human standards. Many people walking by a grass in bloom, would not even recognize that the plant was in flower. Not all botanists completely agree on what a graminoid is. For instance, some exclude the cattails.
Graminoids include these plant families:
True Grasses – Poaceae
Sedges, bulrushes – Cyperaceae
Cattails – Typhaceae
Graminoids grow pretty much everywhere other plants do on land, from hot deserts to wetlands, forests, tundra, and of course, grasslands. Most graminoids are pollinated by the wind, but some get help from insect pollinators. They distribute their seeds by dropping them next to the parent plant. Sometimes they will be carried off by rodents and dropped further from the plant if the seeds are not eaten. There are always exceptions to the rule in nature, though.
Graminoid plant species dominate many wetlands: Phragmites, wild rice, burreed, and tussock sedge are just a few examples. Without graminoids, wetlands and other ecosystems would be very different. Birds, mammals, invertebrates, and other wildlife rely on graminoids for food, cover, and nest-building materials. Thick stands of grasses or sedges are great places to hide or build a nest and raise young. The seeds dropped by many species are nutritious sources of food for ducks, sparrows, rails, and small mammals. Masses of roots, leaves, and stems are heaped together by muskrats to make their lodges.
Graminoids grown in and out of wetlands provide most of the food for humanity either directly or indirectly. Wheat, rice, corn, oat, and a host of other grains are grass seeds we eat without much modification or ground into flour to make breads and pastas. Wild grasses and domestic grains provide feed for cattle, hogs, and chickens, and we eat them. Without our graminoid friends, we would starve. Domestic rice and wild rice are both wetland grasses that have, and continue to be, one of the primary sources of calories for cultures worldwide.