This year we’ve been making a major effort to document the various species of plants, animals, and fungi that are found on CWC properties. This includes both new searches and reviews of photographs and other documentation from past years. If we have photographs of a species, the images are being uploaded to the website iNaturalist so that they may be available to everyone. (Check out our iNaturalist observations at https://www.inaturalist.org/observations?user_id=cwcnaturalist.)
Most species that we have encountered are common, but there have been several discoveries of species that are not well documented in our service area, including several species of orchids. While many of these less-documented species have very specific habitat requirements, most would be considered uncommon but not rare. However, in early September, a plant survey uncovered a truly rare plant in one of our preserves along the Chippewa River. (Because of the rarity of this plant we are keeping its exact location a secret.)
The Forked Aster (Eurybia furcata) is found only in six states ranging from Michigan south and west to Iowa and Missouri. It has only been previously recorded in three Michigan counties: Midland, Mason, and Monroe. In the latter, the last sighting was in 1906. The plant is considered rare across its range with less than 120 known populations. In Michigan, Forked Aster is a state-threatened species. The species has a similar status and associated legal protections across its range, with the exception of Missouri where it enjoys no legal protections.
Forked Aster is one of two species in the Eurybia genus to be found in Michigan with the other species Big-leaf Aster (E. macrophylla) being common across the state. At first glance, Forked Aster bears a superficial resemblance to the Flat-topped White Aster (Doellingeria umbellata). Both species have flattened umbels of compound flowers with white rays (petals) and yellow disc flowers but the leaves are very different. The leaves of D. umbellata are long and narrow with smooth margins while those of E furcata are ovoid or heart-shaped with toothed margins.
It was this combination of features which brought the Forked Aster to our attention. While photographing a patch of what we assumed was Flat-topped White Aster we noticed some plants had different leaves. After running through the list of known common aster species, we realized that we might have something special. Eventually, we settled on Forked Aster as the most likely identification. Because of the rarity of the plant we sought confirmation from an outside expert and we were fortunate enough to have a botanist from the Michigan Natural Feature Inventory visit the site and agree with our identification!
So why is Forked Aster so rare? That’s a great question! It may be that the plant has never been common. Like many rare species, it tends to have very specific habitat requirements which limit where the plant may spread – the known populations are mostly confined to floodplains and nearby banks. Forked Aster also seems to be pretty poor at reproducing from seed. However, it is good at spreading by cloning. So even though we found three separate colonies of plants, it is likely that there was very little genetic diversity and each colony is likely composed of only one individual with numerous clones growing from spreading rhizomes.
Discovering a plant such as the Forked Aster on one of preserves shows us the important role that protected lands can play in species conservation. It would have been very easy for us to overlook this plant. On private lands that are open for development, nondiscovery may easily result in the species being eradicated without anyone noting its loss. Now that we know Forked Aster can be found along the Chippewa River in Isabella County, we can be on the lookout for additional populations. Cataloguing species such as this helps the CWC make more informed management decisions of properties and can direct our future conservation and restoration efforts. If you would like to contribute to our efforts to identify and catalogue species with the CWC service area, sign up for a free iNaturalist account and share your observations.
