9. Section Divisae H. Christ
Plants monoecious or dioecious, with
long-creeping rhizomes, forming loose colonies of tufts. Vegetative growth
present, consisting of basal leaves with overlapping sheaths. Flowering stems
erect or ascending, glabrous, light brown to brown at the base. Leaves basal or
nearly so, glabrous. Leaf blades light green, the margins minutely roughened or
toothed, flat or more commonly folded longitudinally. Leaf sheaths with the tip
truncate or nearly so, the ligule wider than long and rounded, the ventral side
thin, white to light brown, lacking vertical, green lines, the lowermost sheath
bases light brown to nearly black, the remains of previous years’ leaves
persistent, degrading into a mass of fibers. Inflorescences with few to
numerous spikes, these mostly crowded into a headlike mass at the stem tip, the
individual spikes sometimes difficult to differentiate, ascending to spreading,
the bracts scalelike, ovate to linear, usually awned at the tip, shorter than
the spikes, lacking a sheath. Spikes all pistillate or staminate, or staminate
toward the tip and pistillate toward the base, sessile, broadly ovate-elliptic
in outline, 1–2 times as long as wide. Staminate scales narrowly elliptic-ovate
to ovate, rounded to more commonly sharply pointed at the tip, straw-colored to
brown with lighter margins and frequently a green or straw-colored midrib.
Pistillate scales as long as or slightly longer than the perigynia and usually
concealing them, ovate to obovate, pointed at the tip and occasionally
short-awned, straw-colored to brown with lighter margins and frequently a green
or straw-colored midrib. Perigynia ascending, unequally biconvex with 1 side
flattened and the other side broadly rounded, ovate, the margins angled but not
winged, tapered to a beak with minute teeth along the margins and 2 narrow
teeth at the tip, angled or rounded below the fruit to a minute, stalklike
base, glabrous. Styles withering during fruit development, jointed to the main
body of the fruit, which is minutely beaked at maturity. Stigmas 2. Fruits
ovate-elliptic in outline, biconvex and somewhat flattened in cross-section,
yellowish brown. About 12 species, North America, South America, Europe, Asia, Africa.