126. Carex laevivaginata (Kük.) Mack.
Pl. 66 j–o; Map 242
C. stipata Muhl.
ex Willd. var. laevivaginata Kük.
Flowering stems 30–100
cm long, sharply trigonous and often narrowly winged, soft and easily crushed,
often flattening upon drying. Leaf blades 2–40 cm long, 3–6 mm wide, green.
Leaf sheaths truncate or shallowly concave at the tip, the dorsal side white
with green veins or mottled green and white, also with scattered, short, dark
green or brown cross-lines (these actually darkened cross-walls of the cells,
clearly visible with magnification), the ventral side thin, papery, white, not
cross-wrinkled, the tip thickened and yellow, usually not breaking up at
maturity, the ligule longer than wide and V-shaped. Inflorescences compound
with relatively short basal branches, with 10–20 spikes. Pistillate scales
2.5–4.0 mm long, white or nearly so with a green or straw-colored midrib.
Perigynia 4.5–5.2 mm long, 1.6–2.0 mm wide, ovate-triangular in outline, light brown
to reddish brown, the tip tapered gradually to a beak about as long as to at
most 11/2 times as long as the main body, the base truncate, usually
straw-colored, somewhat swollen with spongy tissue but continuous with the main
body and not differentiated into a disklike structure, the ventral surface with
usually 7 strong nerves, the dorsal surface with 9–12 strong nerves. Fruits
1.5–2.0 mm long. 2n=46. May–June.
Uncommon and sporadic
in the Ozark Division and the Crowley’s Ridge
Section of the Mississippi Lowlands (eastern U.S.
and adjacent Canada west to Illinois and Missouri).
Acid seeps, fens, sandy banks of streams, and less commonly in bottomland
forests; also in ditches.
This uncommon species
has been collected most frequently in acid seeps of Crowley’s Ridge but in the Ozarks is nearly
restricted to fens.