Nature Notes
White Blooming Plant' Could Be One of Many on Island
By Patricia Martin

Not a week goes by that I don't get asked to identify a plant from a description. This happened several times this week, and I did my best to try to name the plants from the description I had been given. I'm usually pretty good at it. Now, some people are much better at describing plants to me than others. Some folks have a good eye for noticing detail and know what is helpful in identifying plants, and others are not. This week I may have named one plant incorrectly because I didn't question the person closely enough. The basic description I received was "a maple-leaved plant with white flowers." My first thought was, it must be the Thimbleberry, as they fit the description and are blooming right now, and I shared this with the questioner. Afterward, I realized that description could also fit at least one other plant, which is also blooming on the Island. If the person in question reads this column, perhaps they will be able to recognize the plant they saw.

Thimbleberry (Rubus parviflorus) is in the same genus as the raspberry that grows so abundantly in disturbed areas on Mackinac. Thimbleberry has a special association with the Island, as Thomas Nuttall, a botanist and naturalist, who in the early 1800s traveled to Mackinac and collected plants, discovered the thimbleberry on Mackinac. It had never been identified before and so the species type came from Mackinac.

Highbush Cranberry

Thimbleberries grow in open woods and meadows and bloom in the early summer. The plants stand three to six feet tall and the leaves resemble maple leaves in shape and are arranged alternately along the branch. These often five-lobed leaves are coarsely toothed and are four to eight inches across. The veins of the leaves are prominent. The flowers that are blooming right now are white and showy, one to two inches across. There are five petals and they are oval. The stamens in the center of the flower are many and yellow. Around the blossom are five long, green, pointed sepals. Later in the summer the fruit will appear. It is an aggregate fruit with many seeds, red, and shaped like a thimble.

The fruit of this plant is edible but tart, and has often been prized for its use in jams and pies. This plant has also been used for medicinal purposes. A tea made of root bark of the thimbleberry, and all of the raspberries, has been used to cure diarrhea, prevent vomiting, and control dysentery. The fruit, when chewed, is supposed to remove tartar deposits on the teeth. Root bark tea was also used to wash sore eyes. The leaves can make a tea that was used as a gargle to relieve irritated and sore throats. Extracts from the leaves have been used to alleviate labor pains. Tea from either the roots or leaves has been used as a wash to help heal wounds and sores.

Thimbleberry

Another white flowered, maple-leaved plant now blooming on the Island is the highbushcranberry or cranberry viburnum (Viburnum trilobum). This shrub stands up to 12 feet high with woody, gray barked branches. The leaves are arranged oppositely along the stem, obviously growing in pairs. They are threelobed and coarsely toothed. The leaves are palmately three to five ribbed, rounded at the base, and have smooth sinuses between the lobes. The flowers are arranged in clusters with a rim of large, showy, white flowers around the inflorescence. Just one of these white edge flowers can be an inch across. The fruit, which develops later in the summer, is a red, round drupe, which is edible, though sour, until the first strong frost hits, when it turns sweeter. These berries can be made into jam, jelly, pies, or added to pancakes or muffins.

These shrubs are found along shores, stream banks, in cool moist woods, and rocky slopes. On Mackinac there are a fair number found along the East Bluff and scattered throughout the woods of the east side of the Island.

In addition to the use of the berries as food for people, animals, and birds (often in the winter these red berries are the only bright color in the woods), the inner bark of the highbush cranberry was made into a tea by the Menominee and used to relieve cramps and colic. The Chippewa made a decoction from the inner bark of tag alder and highbush cranberry and ingested the tea as an emetic.

These are two "white flowered, maple-leaved plants" that are blooming right now on the Island. There may be others, and I'll have to think about it. I hope you can differentiate these two among the variety of white flowering plants on Mackinac.

Trish Martin is a year-around resident of Mackinac Island, has earned a master's degree in botany from Central Michigan University, and owns Bogan Lane Inn.