Carex viridula

Carex viridula, known as little green sedge, green sedge, or greenish sedge, is a small flowering plant native to North America, Europe, Asia, and Morocco.[1]
Taxonomy

Carex viridula is in the section Carex sect. Ceratocystis, a circumboreal group with around six other species, although the taxonomy of this group is controversial and up to 19 species have been recognized.[2][3]

Flora of North America accepts the following three subspecies and two varieties of Carex viridula:[1][4]

Carex viridula subsp. brachyrrhyncha
Carex viridula var. elatior
Carex viridula var. saxilittoralis
Carex viridula subsp. oedocarpa
Carex viridula subsp. viridula

As of December 2019, Kew's Plants of the World Online lists Carex viridula as a synonym of Carex oederi.[5]

There is also variety Carex viridula var. bergrothii (Palmgr.) B.Schmid (synonym Carex bergrothii Palmgr.).[6]
Conservation status

It is listed as endangered in Connecticut[7] and Pennsylvania.[8] It is listed as threatened in Illinois.[8]
References

Crins, William J. (2002). "Carex viridula". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). Vol. 23. New York and Oxford. Retrieved 20 December 2019 – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
Crins, William J. (2002). "Carex sect. Ceratocystis". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). Vol. 23. New York and Oxford. Retrieved 20 December 2019 – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
Jiménez-Mejías, Pedro; Luceño, Modesto; Martín-Bravo, Santiago (1 March 2014). "Species Boundaries within the Southwest Old World Populations of the Carex flava Group (Cyperaceae)". Systematic Botany. 39 (1): 117–131. doi:10.1600/036364414X677973. S2CID 85265989.
Crins, W. J. and P. W. Ball. 1988. Sectional limits and phylogenetic considerations in Carex section Ceratocystis (Cyperaceae). Brittonia 40: 38–47. Crins, W. J. and P. W. Ball. 1989. Taxonomy of the Carex flava complex (Cyperaceae) in North America and northern Eurasia. II. Taxonomic treatment. Canad. J. Bot. 67: 1048–1065.
"Carex viridula". Plants of the World Online. Royal Botanical Gardens Kew. Retrieved 20 December 2019.
"Carex bergrothii Palmgr". www.worldfloraonline.org. Retrieved 6 February 2021.
"Connecticut's Endangered, Threatened and Special Concern Species 2015". State of Connecticut Department of Energy and Environmental Protection Bureau of Natural Resources. Retrieved 19 December 2019.
"Plants Profile for Carex viridula (little green sedge)". plants.usda.gov. Retrieved 19 December 2019.