A robust stoloniferous floating perennial with long hanging roots and scaly stolons. Stolons 5-20 cm long and 2-3 mm wide with 2-3 cm long blackish scales, rooting at the nodes, spreading horizontally and producing new plants at their apices. Stem 45-70 cm tong and 3-5 mm thick, sharply triangular, smooth. Leaves all basal or nearly so, 40-90 cm long and 4-10 mm wide, usually much longer than the culms, often purple and strongly V-shaped below, flat above; midrib protruding below, longitudinal ridges narrow; margin and midrib with minute spine-like teeth (i.e. scabrid); lower leaf-sheaths inflated with longitudinal veins and some cross-veins (only conspicuous from outside); ligule a low rim with densely set hairs on the margin. Inflorescence of 3-10 subumbellately arranged heads and with peduncles of usually very variable length. Inflorescence-bracts leafy, the longest 30-60 cm long and 4-9 mm wide; each bract subtending one inflorescence head. Peduncles 1-35 mm long and 0.6-1.8 mm thick, set in a purple-stained tubular prophyll with ciiiate margin. Inflorescence-heads 5-15 mm across, globose or hemispheric (rarely triangular in outline), with numerous closely packed spikelets. Spikelets 3.5-6.0 mm long and 2.5-3.5 mm wide, subtended by scale-like bracts with short leafy apices, but with no prophylls. Glumes about 3.5 mm long, very stiff, reddish brown but sometimes with a paler greenish mi-drib; longitudinal «nerves» indistinct, uncoloured and not protruding; keel of the midrib glabrous or set with spine-like teeth; margin with long ciliate hairs; apex very thick, acuminate. Stamens 3. Style-branches 2. Nutlet 2.6-3.0 mm long (including a 0.7 mm long beak) and 0.6-0.8 mm wide, elongate with cuneate base and ending in a long beak, glabrous, yellowish but brown at the base and in the centre, floating.
Home