Platanthera orbiculata (Pursh) Lindley. Subgenus: Platanthera. Section: Lysias. Large Round-leaved Orchid, Dessert-plate Orchid. Phen: Jun-Sep. Hab: Moist hardwood forests and seeps, especially over mafic, calcareous, or other more nutrient-rich substrates. Dist: NL (Newfoundland) and NL (Labrador) west to AK, south to PA (and in the mountains to NC and TN), OH, IN, MN, SD, and OR.
Origin/Endemic status: Native
Syn: = FNA26, Il, K3, K4, Mi, NE, NY, Pa, Tn, Va; = Habenaria orbiculata var. orbiculata – C, F; = Lysias orbiculata – S; = Platanthera orbiculata var. orbiculata – K1, Luer (1975); < Habenaria orbiculata – G, RAB, W, WV, Correll (1950)