This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol1", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Marsh herbs with rush-like leaves and small spicate or racemose perfect flowers. Perianth 4-6-parted, its segments in two series, persistent or deciduous. Stamens 3-6. Filament's very short or elongated. Anthers mostly 2-celled and extrorse. Carpels 3-6, 1-2-ovuled, more or less united until maturity, dehiscent or indehiscent. Seeds anatropous. Embryo straight.
Four genera and about 10 species of wide geographic distribution.
Leaves all basal; flowers numerous on naked scapes, spicate or racemed.
Stem leafy; flowers few in a loose raceme.