One of various plants and seaweeds growing in the sea: (a) a pondweed, Ruppia maritima; (b) the eel-grass or grass-wrack, Zostera marina; also, the…

Seaweed; esp. a seaweed of the genus Fucus or the genus Sargassum, growing in intertidal waters and on rocks and corals in coastal areas.

Some tree-like seaweed.

A kind of seaweed. Obsolete. rare.

a kind of seaweed.

A seaweed found in the Channel Islands, used for fuel and manure.

A particular kind of seaweed.

a species of seaweed.

? a species of seaweed.

name for two marine plants with long narrow grass-like leaves: (a) Thalassia testudinum, of the W. Indies, etc.; (b) the grass-wrack, Zostera marina.

A dark-coloured seaweed. ? Obsolete.

Any of various red algae from which agar may be extracted (cf. agarophyte, n.); esp. any of several South-East Asian seaweeds of the genera Gracilaria…

(Usually as two words.) A green alga.

any of several varieties of large seaweed found in Pacific and Antarctic waters; cf. bull-head kelp at kelp, n.1 1a.

Any of various seaweeds from which agar can be extracted. Cf. agar-agar, n. 1.