Publication: Cas. Nár. Mus., Odd. Prír. 140: 127. 1972.
selected vouchers: WTU
Notes: Not in H&C; collected by PZ/FW from Ridgefield NWR.
FNA23: "Schoenoplectus subterminalis often forms lawnlike, underwater mats that are entirely vegetative or have only the inflorescences emergent. This species is probably extirpated from Illinois. Schoenoplectus subterminalis var. terrestris Paine [= S. subterminalis forma terrestris (Paine) Fernald] probably does not deserve taxonomic recognition."