Equisetum ferrissii Clute. Phen: May-Aug. Hab: Riverbanks, wet forests. Dist: There are old reports, repeated in RAB, S, and FNA, of the occurrence of E. ×ferrissii in NC and SC; documentation of these reports is not known; it is reported for Prince George's County, MD (Shetler & Orli 2000), for KY (Campbell & Medley 2007), and for all 75 counties of AR (Peck 2011).
Origin/Endemic status: Native
Taxonomy Comments: This is the hybrid of E. laevigatum and E. praealtum (= E. hyemale ssp. affine). It behaves as a species, often occurring independent of one or both parents.
Synonymy: = G; = Equisetum ferrissii Clute – Ar, C, FNA2, GrPl, Il, K1, K3, NE, Pa, TxFerns, Christenhusz et al (2019); = Hippochaete ×ferrissii (Clute) Škoda & Holub