Najas malesiana W.j.de Wilde

Up to 15 cm, lower internodes 1-3 cm by 0.5-0.8 mm. Leaves (1.25-)2(-2.5) cm by (0.4-)0.5-0.7(-0.9) mm, flat, apex obtuse or slightly acute (blade c. 3 mm below the tip 0.25-0.5 mm wide); margin on either side with (20-)25-30(-50-60) inconspicuous teeth, mainly consisting of the spine-cell; dorsal surface without spines; spine-cells (0.05-)0.1(-0.25) mm, (dark) brown; midrib c. 0.05 times as wide as the blade, cavities occupying up to half the width of the blade, often with distinct septa. Sheaths (1.5-)2-2.5(-3) by 1-2.5 mm, on either side with (2-)6-14 spines, 0-4 spines on the inner edge of the auricle; auricles long-triangular or linguiform, sometimes falcate, 0.5-0.8(-l.l) by 0.3-0.8 mm, entire (rarely shallowly lobed). Female flowers often up to 3 together, in different stages, together with one male (often appressed to the female), or male solitary. Male flowers without spathe; anther 1-celled, elliptical-oblong, apically sometimes narrowed, 0.6-1 by 0.15-0.3 mm; 'perianth lobes' often indistinct; 'pedicel' 0.2-0.4, at anthesis c. 1 mm. Female flowers: spathe absent; rarely up to 0.3 mm stalked; (1.2-)1.5(-1.8) mm; ovary 0.4-0.8 by 0.2-0.3 mm; style 0.25-0.5 mm, with 2(-1) stigmas 0.3-0.6 mm. Seeds (0.9-)1-1.5 by (0.35-)0.4-0.5 to 1.5-1.8 by 0.5-0.6 mm; testa with 16-26 length-rows of 24-30 subquadrate or 5-6-angular areoles.

In streams and pools often in the forest, in swamp forest (Tjitjadas), more rarely in rice-fields (Setul, Padang), at low and medium altitude, once at 900-1000 m (Padang).