Lakeshore Bulrush

Perennial, 50-150 cm. Rhizome horizontal, 7-8 mm diam. Stem 3-10 mm diam., terete, soft. Sheaths up to 40 cm, soft, mouth oblique, margins scarious; blades normally reduced to mucro on tip of oblique mouth margin of sheaths, sometimes, esp. when submerged, up to 30 mm, or longer, channelled, pointed. Inflorescence 50-90 mm, pseudolateral multiple spike or small anthelodium; lowest bract 33-55 mm, erect, thick, almost terete, adaxial surface present as narrow strip, apex acute; primary branches c. 8, up to 60 mm, scabrous; each supported by glume-like bract, up to 15 mm, truncate, margins scarious, often fringed; tubular prophyll to c. 10 mm, binerved, sterile, mouth oblique, widely scarious, often fringed; secondary multiple spikes with 2-12 spikes; secondary branches to 17 mm. Spikes 4-10 x 2-5 mm, ovoid; glumes 2.8-4.3 mm, widely cymbiform, mid-nerve extending into smooth or barbed mucro up to 0.7 mm, margins widely scarious, apex rounded, fringed. Perianth bristles 5-7, equalling nut or slightly longer, reddish brown; stamens (2-)3, anthers 1.5-2.7 mm, with reddish brown, barbed connective tip; stigmas 2 or 3. Nut 1.6-2.7 x 1.1-1.8 mm, obovoid, bi-convex or triangular, plano-convex, apiculate, finely reticulate.

Distribution: All Europe, east to Japan, in the south to Turkey, Caucasus, Iran, Afghanistan, Pakistan and Kashmir.

Scirpus lacustris L., Sp. Pl. 1: 48. 1753; C.B.Clarke, l.c. 568; R. R. Stewart, l.c. 101; Nyárády in Fl. Rep. Soc. Romania 11: Pl. 114. 1966.