Geum geniculatum Michaux. Phen: Late Jun-Aug; Aug-Sep. Hab: Seeps, seepy boulderfield forests, grassy balds, cliff bases, banks of cool streams up to about 5 m wide, at high to moderate elevations. Dist: G. geniculatum is apparently restricted (though locally fairly common in the prime habitats) to the few highest peaks in nw. NC and ne. TN: the Roan Mountain massif (Roan High Knob, Roan High Bluff, Round Bald, Jane Bald, Grassy Ridge, Little Hump Mountain, Big Yellow Mountain, and Big Hump Mountain; Avery and Mitchell counties, NC, and Carter County, TN), Grandfather Mountain (Avery, Watauga, and Caldwell counties, NC), and Rich Mountain (Watauga County, NC). Also recently discovered (August 2021) by Amanda Treher on Whitetop Moutain in Washington County, VA where it appears to naturally occur in and around seepage areas (Virginia Botanical Associates 2022).
Origin/Endemic status: Endemic
Other Comments: It may be found on a few other peaks, such as Snake Mountain. The distribution of this species is peculiar. While limited to the several highest and coldest mountains in the Southern Appalachians, it extends downslope on Roan Mountain and Grandfather Mountain nearly to their bases, in environmental situations that are apparently duplicated on many other Southern Appalachian peaks. Perhaps G. geniculatum was more widespread in the Southern Appalachians in the cooler, moister conditions of the post-Pleistocene, but became restricted to the few coldest peaks during the warmer, drier conditions of the Hypsithermal Interval (7000-2000 B.C.). Following climatic cooling, it was able to disperse downslope from its several refugia, but has not dispersed successfully to other peaks. G. geniculatum is most closely related to the circumboreal G. rivale, with which it shares such characteristics as purplish, non-reflexed sepals, a relatively long terminal style segment, upper pedicel with long glandular hairs, and basal style segment with long glandular hairs. See Shattelroe et al. (2021) for detailed discussion.
Synonymy: = FNA9, K1, K3, K4, RAB, S, Tn, W, Bolle (1933), Robertson (1974); = n/a – C