Annual or perennial submerged herbs; rhizomes creeping, branched, rooting at nodes. Stems 4–16 cm, 0.3–0.4 mm in diam. Leaves sub-opposite, or whorled,  3–10 cm x 0.3–0.5 mm, apex acuminate; sheaths  usually free from leaf base, stipuliform, membranous. Flowers brownish. Anthers 0.5–0.9 mm; filaments ca. 2.5 mm. Style shorter or as long as the body of the achene. Achenes often curved, reniform to semilunate, 1.5–3 mm.

Distribution: Nepal, E Himalaya, Tibetan Plateau, Assam-Burma, S Asia, E Asia. 

Altitudinal range: 100−1100 m. 

Ecology: Occurs in fresh water. 

Flowering & fruiting time:  March−June. 

Notes:

One submerged specimen of Potamogeton collected at Rara Daha, Mugu district, west Nepal at 9800 ft. by O. V. Polunin, W. R. Sykes and L. H. J. Williams (no. 5154) on August 13^th, 1952, has been identified by Z. Kaplan as Potamogeton gramineus L. The specimen also looks like Potamogeton lucens L. due to presence of short petiole. The submerged leaves of Potamogeton gramineus are sessile. More specimens would be required to enable a better understanding of this species. 

Expected species from Nepal: 

Stuckenia pamirica (Baagoe) Z. Kaplan

  Potamogeton pamiricus Baagoe

  Potamogeton recurvatus Hagstr.

 Stuckenia amblyophylla (C. A. Mey.) Holub

  Potamogeton amblyophyllus C. A. Mey.