Northern Prairie Wildlife Research Center
SEDGE FAMILY (Cyperaceae)
IND. STATUS: OBL
FIELD CHARACTERISTICS: A perennial herb from long rhizomes. The stems are sharply triangular with 2 or 3 concave sides, and grow to a height of 15 dm. The leaves form basal sheaths and are less than half the height of the stems. Spikelets number 1-8 and are 7-20 mm. long, sessile, crowded, and oblong oval. A specialized leaf resembles a continuation of the stem beyond the spikelets. Nutlets are (2.3)2.5-3 mm. long, with bristles that are as long to two-thirds as long as the nutlet. In flower from July to September.
ECOLOGICAL NOTES: Three-square bulrush is a persistent emergent found in deep and shallow marshes, calcareous fens, and borders of lakes and streams, often in water depths of 1 foot and up to 2.5 feet. It is frequently found in mixosaline waters. Three-square bulrush is an excellent wildlife food plant. Formerly known as S. americanus Pers., a name that was misapplied to the three-square bulrush found in Minnesota (Ownbey and Morley 1991).
SOURCE: Fernald (1970); Gleason and Cronquist (1991); and Voss (1972).