1. Cladium mariscus (L.) Pohl, Tent. Fl. Bohem. 32. 1809; Boiss., Fl. Or. 5: 392. 1882; C.B.Clarke, l.c. 673; R.R.Stewart, l.c. 86; Kukkonen in Rech.f., l.c. 156.
Schoenus mariscus L., Sp. Pl. 1: 42. 1753.
Perennial, to more than 1 m, forming large pure stands. Rhizome creeping or stoloniferous, sturdy. Stem to c. 6 mm diam., with more than 10 internodes, terete, hollow, smooth, grey green. Leaves arranged spirally along whole stem length, up to nearly equalling stem; basal sheaths, e.g., 15 cm, hard, persistent, grey-brown or blackish brown; ligule 0; blades often more than 50 cm, 5-9 mm wide, unifacial, flat or folded, grey-green, midrib below and margins sharply scabrous, apex long-attenuate, trigonous, scabrous. Inflorescence of partial inflorescences in more than 6 leaf axils, upper overlapping; bracts much longer than partial inflorescence, except at stem apex; partial inflorescence a compound anthelodium, occasionally much elongated, to 15 x 10 cm, peduncle to 25 cm; primary branches (0-) 25-100 mm, secondary branches to 35 mm, ending with cluster of spikes or tertiary anthelodium, tertiary branches to 15 mm, mostly ending with cluster of spikes; ultimate branches with bracts, 3-5 mm, and tubular prophyll; cluster of spikes by 3-14, mostly sessile spikes; spike fusiform, c. 4 mm, glume-like bract c. 1 mm, glume-like prophyll c. 1 mm; lowest 2-3 glumes sterile, 1.2-3 mm, in axil of 4th glume a unisexual flower with two stamens (occasionally bisexual); in axil of 5th glume a bisexual flower with, mostly, two stamens and pistill, mostly tristigmatic. Nut 2.9-3.3 x 1.4-1.6 mm, fusiform, yellow brown, smooth, glossy, base more or less differentiated disc, apex conical.
Type: ’Habitat in Europae paludibus’.