Sweetbriar, Prairie Rose Are in Bloom on Mackinac Island Nature Notes By
Patricia Martin

Well, surely it’s now summer. The streets are busy, the boats are running non-stop, and the weather has warmed up, to say the least. The summer flowers are also starting to bloom.

If you wander around on the south end of the Island, the Cedar woods are ablaze with a brilliant yellow hawkweed known as Golden Lungwort. This European species is only found in a few counties in Michigan, Mackinac being one of them. It loves to grow on limestone soils and so prospers on the Island and grows in profusion beneath the Northern White-cedars in areas where few other plants flourish. (I wrote about them in a previous column.)

Shin Leaf

Another summer favorite that has shown its head is the Wood Lily. This tall, large, showy flower is reminiscent of the Asiatic or Tiger lilies with its brilliant orange/red flowers and its narrow leaves. It can be found along wooded roads in the interior of the Island, but, surprisingly enough, it’s also found along the shore road.

Along the shore road blooming in great abundance, are the wild roses. They’re also found in the interior, in open areas. There are a number of these plants blooming on the Island, including Sweetbriar ( Rosa eglanteria ), Swamp Rose ( R. palustris ), Prairie Rose ( R. askansana ), and several just known as Wild Rose ( R. aricularis ) and Smooth Rose ( R. blanda ). These last two are some of the more common ones here.

In general, the roses have showy white or predominantly pink flowers up to three or four inches in diameter, made up of five petals surrounding a central yellow disk supporting numerous stamens. The leaves of the roses have three to nine leaflets arranged along a central stem (pinnately compound) with stipules attached to the base of the leaf stalks. Some of the roses have sharp thorns scattered along the stem while others are quite smooth on the upper branches. These plants have a shrub form and are most commonly found where they will get a good bit of sun. The cultivated tea roses have been developed from these wild ones and have been bred to have multiple layers of petals.

Probably the flower that I was happiest to see this week can be found in the areas of the Island which have deciduous trees in moist to somewhat dry soil, mostly in the interior. It is commonly called Shin Leaf ( Pyrola elliptica ) and it was first identified by an early naturalist named Thomas Nuttal. Thomas Nuttal actually came to Mackinac in 1810 and spent a few days on the Island and in the area collecting a variety of plants, including the species type of the Dwarf Lake Iris (Iris lacustris).

Shin Leaf is in the Heath family ( Ericaceae ). It’s only five to 10 inches tall with white, nodding, waxy blossoms arranged in a loose spike. The flowers are composed of five petals, often with green veins. A long, curving pistil extends beyond the petals. Looking at them from above they remind you a bit of Lily-of-the-valley; in fact, this species is sometimes called Wild Lily-of-the-valley. Like Lily-of-the-valley, they’re usually quite fragrant.

The leaves of the Shin Leaf are quite different from the Lily. They’re only found at the bottom of the plant with the leaf blades longer than the leaf stalk and longer than broad (up to three inches long). The leaves themselves are not shiny and the leaf blades are thinner than many of the other Pyrolas. The blade of the leaf flows into its leafstalk and its color is dull green. The stem of the Shin Leaf is smooth and leafless in the upper portion.

This is the most common of all of the Pyrolas. These are one of the relatively few herbaceous species blooming in midsummer in deciduous woods and therefore the white flowers are rather conspicuous. The ones I spotted while riding my horse were along the north end of Jupiter Trail and along Lost Bear Trail. I’m sure you can spot them in a number of other places.

We have several other species of Pyrolas that will be blooming throughout the summer. One is known as Green Shin Leaf ( Pyrola chlorantha ) and as its name implies, has flowers that are more greenish in hue than the Shin Leaf. These have spikes of two to 13 flowers with protruding styles. The smaller leaves are more rounded than those of Shin Leaf and the stems are naked with perhaps a scale part way up. These plants are found in moist to rather dry coniferous or mixed woods, often in moss or in the litter of conifer needles.

These are but a few of the flowers that are blooming right now. While you’re out you will also see Tall Buttercup, an escaped Foxglove, Wild Comfrey, a number of mints including Wild Basil and Selfheal, and the list goes on and on. Enjoy the wild flowers of summer.

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.