Isle Royale poses some challenges for flower identification. It is in Michigan, but lies off the Minnesota and Ontario shores - - so its selection of flowers overlaps with those in all three states. The region is characterized by three different forest types: early succession (aspen and paper birch), more boreal spruce-fir forests, and northern hardwoods (maple-birch) forests. Each has a distinctive set of wildflowers, as do the different smaller habitats such as wetlands, exposed rock, and the like.
In addition, not all of the mainland species made it over to the island. As a result, the mix of species differs from the mixes found on the mainland. I’m always struck by how prevalent thimbleberries are on Isle Royale compared to the mainland.
The distinctive elements of an island climate also shape the mix of wildflowers. Thanks to Lake Superior, Isle Royale has a more moderate climate than comparable inland areas nearby. It also tends to be moister. This too gives the island a different mix of flowers than the mainland, so a standard guide to (say) Michigan wildflowers might not be as helpful as you would like.
Finally, most visitors are on the island only during a six-week period in July and August, so they observe only a small part of each plant’s annual life. For example, I don’t think I’ve ever seen thimbleberry flowers, though I’ve seen lots of the berries. If the flowers were important for identification, as they are for some species, this would complicate matters.
Because of these challenges, I thought it would be helpful to bring together an album of Isle Royale wildflowers, emphasizing identification. I’m far from expert, and welcome any help - - and pictures! - - that you can provide.
Resources for Further IdentificationThe NPS site has a page of Isle Royale plants. This page is far from complete, and many of the pictures are small. However, it has the advantage of putting all the plants on one page.
Robert Janke’s Wildflowers of Isle Royale is apparently the only book dedicated just to Isle Royale flowers. It relies mostly on sketches of the plants. This is good for the leaves and overall structure of the plant but not so useful for berries. It is also incomplete.
Wildflowers of Ontario is a wonderful site maintained by a retired teacher, John Wright. You can search by color and by the shape and number of petals in the flower. Most Isle Royale wildlflowers are found somewhere in Ontario, and may be found here.
Charles Peirce, another teacher, maintains a site for Michigan wildlflowers. This is a good reference, with several pictures of each flower on each page. However, you have to know the name of what you’re looking for first. The pages also load very slowly.
Minnesota’s Department of Natural Resources has an exhaustive site that is more valuable as a reference than as an identifier. In other words, if you think you know what you have, you can confirm it here, but it doesn’t provide multiple flowers on the same page for searching. It also emphasizes flowers, not berries. Michigan’s DNR maintains a similar site.