Very similar to Soft Rush, J. effusus but darker blue-green, shorter, more slender plant. Earlier flowering, flowerheads spherical, compact. Stems not glossy, bluish-green, strongly ridged, rough to the touch.
Frequent in damp fields, open woodland, ditches and by water.
Avoids calcareous ground, less frequent in central Ireland.
Found in slightly drier habitats than Soft Rush.
Similar: Hard Rush, J. inflexus.
Stems ridged, bluish-green. Flowerheads always loose, open.