Thalassia K.D. König

Submerged, marine, perennial herbs. Stem elongate, rhizomatous or shortly erect, the latter produced from nodes along the rhizome. Roots 1 per node, sand-binding, covered with fine hairs. Leaves sessile, usually 2–6, distichously arranged on the erect stems, linear, distinctly sheathing at the base, opaque or somewhat translucent, margins green, entire. Flowers spathes 1–2 in the leaf-axil, pedunculate, 1-flowered, composed of 2 bracts connate on one side only, translucent; tepals 3, elliptic, cucullate, strongly recurved at anthesis. Fruit globose, beaked, densely hairy, opening by stellate dehiscence of the carpels. Seeds conical with a thickened basal portion.

Worldwide: Two species in tropical waters.

Mozambique: 1 taxon.