Perennial plant. The inflorescence is apical, corymbose-paniculate, 2-8 cm long. The tepals are 2-3 mm long, ovate, obtuse, pale brownish, with a light median stripe and a light membranous border. Bracts are light, not colored. Leaves: Leaf blades up to 1 mm wide, grooved or flat, sharp at the end; the lower leaves are light brown. Height 10-50 cm. The stems are straight, flattened, leafy to the middle, rarely higher. With a shortened horizontal creeping rhizome. The box is spherical or oblong-oval, about 3 mm long, shiny, brownish, longer than the perianth. It blooms in June-August, bears fruit in July-September. Flattened sitnik grows in wet floodplain and dry meadows, along the banks of reservoirs, roadsides.