Forked Aster Blooming in the Bog
Danielle Bell
When you think of the vegetation of the Cedarburg Bog, you may first think of wetland or bog species such as pitcher plants, lake sedge, tamaracks, or skunk cabbage. These are some of the more dominant species found in the center of the Bog where the water level is at the peat surface. But there are microclimates throughout the Bog that boost the floral diversity due to the topographical variations. The upland forest that surrounds the Bog, along with the islands located within the wetland boundaries, contain a mosaic of woodland plants with wet-mesic and mesic forest species located along the edges and dry forest species growing on the top. This variation in topography allows the Cedarburg Bog to be home to over 400 of the Field Station’s 720 vascular plant species.
Recently a new population of a State-Threatened species was found growing at the northern edge of the Bog where the wetland meets the upland. Alex Mann was doing bird surveys one late July day when he noticed an aster in bloom that looked unique. Upon keying out the species, he discovered that it was Forked Aster (Eurybia furcata), a state threatened species with a coefficient of conservatism value of 8. Southeastern Wisconsin and Northeastern Illinois include its historical range, and this species is known to be found in a few of our natural areas remaining in southeastern Wisconsin. However, the Cedarburg Bog was not listed as a known population.
Forked Aster inflorescense
The aster family is one of the trickier plant families to tease apart when it comes to identifying a plant to species. Many species have similar flowers, and a casual look can trick even some well-seasoned botanists. The composite floral displays of Forked Aster are composed of 9-18 ray flowers that can vary from 8-15mm long. Their leaves are rough on the surface and densely hairy on the underside. Asters and Goldenrods are the signal that fall has arrived with their glorious floral displays lighting up the prairies and woodlands in late August and September for one final bang before winter arrives. However, Forked Asters bloom as early as July.
Forked Aster leaf
Forked Aster underside of leaf
In the late 1980s, Lawrence Leitner, Jim Reinartz, and Donald Les conducted a study to learn more about the site requirements of this species, (Distribution and Habitats of Forked Aster (Aster furcatus), A Threatened Wisconsin Plant, UWM Field Station Bulletin, 1991). You can read the complete study here in the Field Station Bulletin. During this research, plants were inventoried at 14 known populations throughout Southeastern Wisconsin and specimens were grown at the Field Station to experiment on its mating system and pollination compatibility.
Forked Aster is a woodland plant that prefers moist soil conditions associated with calcareous soils. Plants are rhizomatic and tend to form colonies in habitats that they find favorable. They are usually found along rivers or lakes in conjunction with Red Oaks, White Oaks, Basswood, and American Beech. All these conditions are found at the margins of the Cedarburg Bog. Unlike most aster species that are known to be prolific propagators via seed, this species produces very few viable seeds. It is a wonder if this is a population that has occurred historically in the Cedarburg Bog and missed during surveys or if it is one of the few viable offspring from the plants that were grown for research back in the 1980s that found the perfect location to take root.
