Of 390 seeds planted in a central Iowa demographic study, 41 emerged (11%) and 18 survivied to year 5; 13 flowered and produced seed after an average of 7.5 years; recruitment of new individuals was also observed (Mabry in prep.).
In a study using tranplants, survival was 94-100% after year 2, with recuitment of new individuals also observed in year 2 (Golay et al. 2013).
Seed output (seeds are ant dispersed) and vegetative spread low (Barkely 1986, Gleason and Cronquist 1991).