- Herbarium ID: NHIC
- Accession Number: MJO74923
- Scientific Name: Carex x knieskernii Dewey (C. arctata x C. castanea)
- Family Name: Cyperaceae
- Location: Approx. 2 km SSE of Shamrock Lk., near Hwy 11, and 20.5 km S of Macdairmid, Ont.
- District Located: not specified
- Longitude/Latitude: 88.11667W / 49.25111 N
- Habitat: Trail through mixed woods.
- Notes: Robust clump, different clump from M.J.O.#25598.
- Collector: M.J. Oldham
- Collection Number: 25599
- Collection Date: 16-Jun-2001
- Determined by: M.J. Oldham
- Annotation by: A.A. Reznicek Feb. 24.