Publication: Cas. Nár. Mus., Odd. Prír. 140: 127. 1972.
selected vouchers: Not at WTU; WS?
Notes: Not reported for WA by FNA. See Madrono 40(3) :179 article. Possibly all early H&C reports of this species in WA are incorrect identifications. C. Bjork reports recent collections from Pend Oreille R. Voucher at WS.
FNA23: "Schoenoplectus heterochaetus hybridizes with S. acutus and S. tabernaemontani (see comment under 1. S. tabernaemontani).
The Michigan record is dubious, the Oregon record is from 1895, and reports from Washington are apparently based on misidentified specimens. Some specimens from scattered localities in Eurasia may be Schoenoplectus heterochaetus."