September 10, 2008
By Susan Benson,
CNHM Director of Education
One of the most important strands in the ecological web of northern lakes and streams is Zizania palustris, commonly known as wild rice. This plant is an annual aquatic grass whose nutritious seeds have long served as valuable food for waterfowl. Within its core range in Minnesota and northern Wisconsin, wild rice is eaten by mallards, blue-winged teal, wood ducks, ring-necked ducks and other species.
This important plant is more than food, however. Wild rice provides roosting and resting areas to adult waterfowl and protective cover for young birds. It also provides habitat for snails, insects and mammals, adding to the biological diversity of the wetlands where it is found.
Wild rice also helps maintain water quality by binding loose soils, tying up nutrients and slowing winds across shallow wetlands. These factors can increase water clarity and reduce algae blooms. Wildlife and water quality are not the only beneficiaries of wild rice, though — this plant has long been a staple food for Native Americans and early European explorers of the region. To the Ojibwa, the plant is called manoomin, a term derived from “Manitou,” meaning Great Spirit and “meenum,” meaning delicacy.
Wild rice flourishes best in shallow, flowing water such as rivers and flowages, and in lakes that have an inlet and outlet. The plant grows in a predictable pattern. Seeds lie dormant in the lake or river sediment through the winter, and then germinate in the spring. In late spring, the new plants grow upward, producing ribbon-like leaves that float on the water’s surface. Through the summer, shoots may reach a height of two to eight feet above water.
In August and September the seeds develop and mature and become ready for harvesting. To the Ojibwa, the August full moon is known as Rice Making Moon, signaling harvest and thanksgiving celebrations. Today’s wild rice harvest methods remain similar to those used for centuries. The ripe grain is harvested from canoes or small boats with the use of smooth, wooden sticks. Generally, two people rice as a team; one moves the canoe through the rice bed using a long push-pole while the other “knocks” the grain from the plant seed heads into the boat. The freshly harvested rice then needs to be finished, a process involving parching to loosen the grain hulls, then winnowing the rice. The end product is a grain low in fat but high in protein, fiber, vitamins and minerals, nutritionally superior to white rice, oats, wheat or rye.
Wild rice can be hurt by pollution, the wake from large boats, exotic species and other factors. As a result many historic rice beds have been lost. Especially damaging are changes in water levels; the lakes and rivers that support rice have often been dammed, and even small increases in water depth can destroy the plant’s habitat. Although wild rice has declined in abundance from historic levels, there is hope that this trend may be reversed. A growing effort is underway to manage and restore wild rice. Tribal, state, federal and private natural resource organizations and interested individuals are working to protect and promote this special resource.
Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 43570 Kavanaugh Street or on the web at http://www.cablemuseum.org/ to learn more about exhibits and programs.