Dryopteris intermedia (Muhlenberg ex Willdenow) A. Gray. Phen: Jun-Sep. Hab: Cove forests, other moist, rocky forests, over a variety of substrates. Dist: NL (Newfoundland) west to MN, south to n. GA and s. MO.
Origin/Endemic status: Native
Taxonomy Comments: This species is one of the diploid "parent species" of the e. North American reticulately-evolved Dryopteris complex. Its genome (symbolized II) forms half of the genome of the tetraploids Dryopteris campyloptera and Dryopteris carthusiana and 2/3s of the genome of the triploid hybrid Dryopteris ×triploidea (Dryopteris carthusiana × intermedia, with chromosome symbolized IIS), which is frequent in areas with both parents present.
Synonymy: = C, FNA2, Il, K1, K3, K4, Mo1, NE, NY, Pa, RAB, S13, Sf, Tat, Tn, Va, W, WV, Montgomery & Paulton (1981); = Dryopteris austriaca (Jacq.) Woyn. ex Schinz & Thell. var. intermedia (Muhl. ex Willd.) Morton – G; = Dryopteris spinulosa (O.F.Müll.) Watt var. intermedia (Muhl. ex Willd.) Underw. – F