Publication: Pflanzenr. 28[IV,20]: 311. 1909.
selected vouchers: WTU
Notes: Some authorities continue to treat C. sitchensis as a separate species e.g. A. Ceska in Illustrated Flora of British Columbia, 2001.
FNA23: "Carex aquatilis var. dives is the most robust variety of C. aquatilis and the only member to have pendent spikes, ellipsoid perigynia, and epistomic leaves. Carex aquatilis var. dives intergrades with var. aquatilis and does not appear to be distinct at the specific level. It may hybridize with C. lyngbyei."