Sibbaldiopsis tridentata (Aiton) Rydberg. Phen: Jun-Aug; Jul-Sep. Hab: Grassy balds, crevices of rock outcrops at high (rarely moderate, or northwards at low) elevations, high elevation glades, sometimes locally abundant. Dist: Greenland and NL (Newfoundland) west to NT, south to e. MA, nw. NJ, ne. PA, NY, n. MI, ne. IL, ne. IA, and SD, and disjunctly southwards in the mountains to w. VA, w. NC, ne. TN, and ne. GA (at progressively higher elevations southward).
ID notes:Showy in flower, and also in leaf from late summer on, when previous year's leaves turn a rich burgundy red (younger leaves staying deep green). Though superficially appearing herbaceous, S. tridentata is really an evergreen sub-shrub.
Origin/Endemic status: Native
Taxonomy Comments: The older epithet ‘retusa’ (1780, based on a type from Greenland) has priority over ‘tridentata’ (1789) (Eriksson et al. 2015); a proposal to reject it by Ertter, Elven, & Reveal (2008) was accepted, and Potentilla retusa O.F. Müller (and other names based on it) have been rejected.
Other Comments: Bresawar & Walker (2011) discuss the genetic structure of populations in e. United States.
Synonymy: = FNA9, Il, K1, Mi, NE, S, Tn; = Potentilla tridentata Aiton – C, F, G, GrPl, Pa, RAB, W, WV; = Sibbaldia retusa (O.F.Müll.) T.Erikss. – Eriksson et al (2015), Feng et al (2017), rejected name; = Sibbaldia tridentata (Aiton) Paule & Soják – K3, K4, NY, Va, Paule & Soják (2009)