Mackinac Island is home to a wide variety of fascinating wildflowers. Overall, nearly 600 species of plants grow on the island and more will surely be discovered. Of these, about 270 are considered wildflowers.
The vast majority of plants generate energy by converting the sun’s rays into food through photosynthesis. This process takes place through spring and summer seasons, utilizing a green pigment called chlorophyll. Chlorophyll begins to fade as autumn approaches, revealing brilliant colors which brighten crisp fall days.
A small number of plants are achlorophyllous, or never contain chlorophyll. Instead, they obtain nutrients by directly parasitizing roots of other plants. Examples include American cancer-root (Conopholis americana), which shows a strong preference for oak roots and blooms in spring. Beechdrops (Epifagus virginiana) grows exclusively on roots of American beech trees, blooming in late summer and early autumn.
Mycoheterotrophic plants get their food by parasitizing fungal networks in the soil. Examples include the familiar ghost pipe (Monotropa uniflora) which blooms in late summer and early autumn. Coralroot orchids are also parasitic. On Mackinac Island, striped coralroot (Corallorhiza maculata) is most commonly found, blooming in spring.
Woodland pinedrops (Pterospora andromeda) also depends on mycorrhizal fungi for nutrients. It can grow much taller than other species shown here, occasionally reaching more than six feet! Amazingly, this species had been missed entirely on all “official” Mackinac Island plant surveys prior to August 2026. It is uncommon here and legally protected in Michigan as an imperiled, “threatened” species. It is also listed as endangered in New York, Vermont, and Wisconsin. Today, it is illegal to pick or disturb this species to help protect it for future generations.
Although pinedrops was not listed on historic surveys, it has occasionally been observed at the Straits of Mackinac. In 1860, Nathaniel Winchell noted the species growing at Rabbit’s Back Peak, near St. Ignace. Avocational botanist Joseph R. Churchill, of Boston, Massachusetts, collected a sample at Mackinac Island on August 2, 1910 in “low spruce woods” near the shore. Today, his preserved specimen is held at the Harvard University Herbaria.
Thomas Nuttall first described this species for science in 1818, based on a specimen collected near Niagara Falls. Nuttall was also the first known botanist to collect plants at Mackinac, arriving here by birchbark canoe on August 12, 1810. The curious scientist described thimbleberry (Rubus parviflorus), dwarf-lake iris (Iris lacustris), and the Lake Huron green orchid (Orchis huronensis) at the straits, among others, but failed to mention pinedrops at Mackinac.
During your next visit, be sure to slow down and enjoy the many natural wonders which abound in Mackinac’s North Woods. Perhaps your observation will add to the enduring legacy of botanical discovery on Mackinac Island.
Posted August 20, 2026
By Kyle Bagnall, Park Naturalist
