Carex retrorsa

Carex retrorsa
Seedheads remain on plant into winter, providing ornamental value
Growing in nursery flats
Conservation status
Least Concern  (IUCN 3.1)
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Monocots
Clade:	Commelinids
Order:	Poales
Family:	Cyperaceae
Genus:	Carex
Species:	C. retrorsa
Binomial name
Carex retrorsa Schwein.
Synonyms[1]
List Carex lupulina var. gigantoidea Dewey Carex retrorsa var. gigantoides Farw. Carex retrorsa var. multispicula Lepage Carex retrorsa var. robinsonii Fernald Carex reversa Spreng.

Carex retrorsa, (commonly known as knotsheath sedge, deflexed bottlebrush sedge, or retrorse sedge), is a widespread species of flowering plant in the family Cyperaceae, native to southern Canada and the northern United States.[1][2]

Description

Carex retrorsa is a clump-forming, rhizomatous sedge. Leaves are bright green and smooth. Basal sheaths are generally brown to purple in colour, often splitting into a ladder shape. Inflorescence consists of multiple spikes, with the terminal spike all-staminate. Bracts are shorter than the lowest pistillate spike. Perigynia are hairless, beaked and toothed, and achenes are triangular in cross-section.[3]

Fruit develops in late spring to summer. Pistillate spikes form clusters of seeds. Each pistillate spike contains 20 to 150 achenes.[3]

Distribution and habitat

Carex retrorsa thrives in stream and lake shores, marshes, swamps, water meadows and alongside waterways.[4] Preferring wet areas and tolerant of some shade, it is available from speciality nurseries for such uses as ecological restoration projects, erosion control, and rain gardens.[5][6]

References

1. "Carex retrorsa Schwein". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 27 September 2022.
2. Quattrocchi, Umberto (2012). CRC World Dictionary of Medicinal and Poisonous Plants: Common Names, Scientific Names, Eponyms, Synonyms, and Etymology. CRC Press. p. 816. ISBN 9781482250640.
3. "Carex retrorsa (Retrorse Sedge): Minnesota Wildflowers". www.minnesotawildflowers.info. Retrieved 2024-12-22.
4. "Carex retrorsa (retrorse sedge): Go Botany". gobotany.nativeplanttrust.org. Retrieved 2024-12-21.
5. Baskin, Carol C. (2003). "Propagation protocol for production of container (plug) Carex retrorsa Schwein. plants, University of Kentucky Lexington, Kentucky". Native Plant Network. US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources. Retrieved 27 September 2022.
6. "Common Name: Retrorse Sedge". nanps.org. North American Native Plant Society. 2017. Retrieved 27 September 2022.