Perennial, 30-100 cm. Stem 1.5-2.5 mm diam., grooved, with 12-15 veins rather densely spaced on both sides, 26-28 vascular bundles in cross section. Lower closed sheath 35-50 mm, dark or black brown, sometimes reddish brown of its whole length, upper 75-175 mm, brown, or dark or reddish brown of whole length or upper part green, later yellowish; blade often present as small mucro. Spike 10-25 x 3-5 mm, with loosely imbricating glumes; glumes 3-3.5 mm, on both sides of midnerve brown or dark reddish brown zone in upper part of glume. Anthers 1.5-2 mm. Nut 1.3-1.6 x 1-1.3 mm (excl. stylopodium), margins slightly protruding and sometimes with a very narrow wing, brown; stylopodium 0.6-0.8 x 0.5-0.8 mm.

Fl. Per.: May - June.

Swamps, wet meadows, 500-2500 m; Distribution: Probably circumboreal, but insufficiently known; Europe, Caucasus, to Afghanistan.

E. palustris s.l. is frequently recorded for Pakistan (Clarke 1898, Stewart 1972). Nevertheless, no reliable material of subsp. palustris has been seen, and the single record of subsp. palustris from Dadu (Abedin & Farooqi 261) by Kukkonen (1998) is here renamed and transferred under subsp. iranica.