Green spikerush, éléocharide olivâtre

Eleocharis olivacea Torrey, Ann. Lyceum Nat. Hist. New York 3: 300. 1836; E. olivacea var. reductiseta (Schuyler & Ferren) Schuyler & Ferren

Culms to 28 cm. Floral scales brown, streaked with green on flanks. Flowers: perianth bristles to 2 times as long as achene, rarely shorter than achene. Achenes green to golden brown when ripe, 0.5–1.1 × 0.4–0.8 mm, apex often highly constricted proximal to tubercle. Tubercles 0.3–0.7 × 0.2–0.4 mm. 2n = 20.

Fruiting summer–winter (Jun–Nov). Bogs, cold springs, dry stream banks, lake and pond margins, maritime mud flats, marshes, moist meadows, swamps; 0–1000 m; N.B., N.S., Ont., Que.; Ark., Conn., Del., Fla., Ga, Ill., Ind., La., Maine, Md., Mass., Mich., Minn., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., S.C., Tex., Vt., Va., Wis.

Eleocharis flavescens var. olivacea was reported from Hawaii; I have not seen a voucher specimen.