Until last week, the only place I had ever seen Aster furcatus (or Eurybia furcata, if you choose to split Aster) was in Warren County, Indiana. I can now add Porter County, Indiana to my list of sites for Forked Aster (or The Forkin' Aster, as I prefer to call it). Unlike many of our state-listed species in Indiana, Aster furcatus is truly a rare plant, known only from Wisconsin, Michigan, Iowa, Missouri, Illinois, and Indiana, and considered a species of conservation concern in all of these states. There are also apparently historic records of the species from Arkansas.
Aster furcatus is considered globally rare or uncommon (G3), and as of 1991, there were less than 50 known populations of this species in existence.
Why is The Forkin' Aster so rare? One explanation could be that it is thought to be self-incompatible. This may be changing, though... more recent research has shown that Aster furcatus is developing self-compatibility, supposedely in response to its existence in small populations.
Another reason why it is so rare may be loss of habitat, in part from succession. Aster furcatus is said to be somewhat shade intolerant. It is a calciphile that is often found on north-facing slopes, along streams, and in seepy areas. It is also found in areas with some disturbance, including along railroads and woodland edges.
As seen in the photograph above, Aster furcatus spreads rhizomatously and forms colonies. This lack of genetic diversity could be yet another reason for its rarity.