The Hummock Sedge is found in the North Temperate Zone south of Sweden to the Canaries, and in W. Siberia. It is not found in any early plant beds. In Great Britain it is absent in the Peninsula province from N. Devon, but occurs throughout the Channel and Thames provinces; not in Hunts in Anglia; is general in the Severn district; in S. Wales it does not grow in Radnor; in N. Wales only in Carnarvon, Denbigh, Anglesea; in the Trent province; in the Mersey it does not grow in Mid Lancs, but is general throughout the Humber and Tyne provinces; Lakes province in Cumberland; in W. Lowlands it does not grow in Renfrew; E. Lowlands, not in Peebles, Selkirk, Roxburgh; not in Mid or S. Perth in E. Highlands; in W. Highlands not in Mid or N. Ebudes; in N. Highlands not in E. Ross, E. Sutherland, but occurs in the Hebrides and Orkneys, and also in Ireland and the Channel Islands.

The Hummock Sedge is a paludal type of sedge, growing in large clumps in wet places or by the sides of rivers, in damp woods, and also in marshes, amongst other common types, such as the Great Prickly Sedge and others.

It has a clustered, bushy habit, with 3-sided stems, which are leafy and stout, rough above. The root is densely aggregated together, forming a tufted surface. The leaves are rough, long, and flat.

The spikelets of the flowers are in a panicle with wide branches, the sterile male flowers at the top. The panicle is three times compound. The fruit is broad, egg-shaped, coming to a sharp point, swollen below, with nerved perigynia, the beak deeply cleft, and the glumes margined. Hummock Sedge is 3 ft. in height. The flowers expand in June and July. The plant is a perennial, propagated by suckers.

The spikelets are bisexual, and male at the top only; the base of the style is swollen. The bisexual flowers are proterogynous, the stigma ripening first, and are pollinated by the agency of the wind.

The fruit is a nut, which falls when ripe into the water or upon the ground.

Like other sedges this is a peat-loving plant, growing in a peat soil.

Two beetles, Cercus pedicularius, C. bipustulatus, and a moth, Elachista paludum, are found on it.

In bogs it forms solid patches which serve as stepping-stones do on moist ground.

Essential Specific Characters: 326. Carex paniculata, L. - Stem thick, triquetrous, with many long, rough, tufted leaves, spikes in a panicle, pale-brown, fruit many-veined, bracts setaceous, nut ovoid.