Carex lenticularis var. lenticularis
Culms 8–60 cm. Leaf-blades 1.5–3.5 mm wide. Inflorescences: peduncle of proximal spike 1 cm or longer; proximal bract white at base, 2–3.5 mm wide. Spikes: proximal 3–7 spikes pistillate, 1.2–6 cm × 2–4 mm,; terminal spike usually staminate. Pistillate scales pale-brown or redbrown. Perigynia (3–) 5–7-veined on each face, ellipsoid or ovoid, 1.7–3.2 × 1–1.6 mm; stipe to 0.1–0.25 mm; beak green or pale-brown, 0.1–0.2 mm. 2n = 86–88.
Phenology: Fruiting Jul–Aug.
Habitat: Seasonally flooded river and lakeshores
Elevation: 0–1500 m
St. Pierre and Miquelon, Alta., Man., N.B., Nfld. and Labr., N.W.T., N.S., Ont., P.E.I., Que., Sask., Maine, Mass., Mich., Minn., N.H., N.Y., Vt., Wis.
Carex lenticularis var. lenticularis is a common shoreline species of ponds and streams in eastern North America. It can usually be distinguished from the common western taxon, var. lipocarpa, by the pale red-brown scales and lack of pigmentation on the perigynia as well as the shorter stipe; some high elevation and high latitude populations have pigmentation patterns similar to the western taxa.
"prolonged" is not a number.