ULVA, in botany; a genus of plants of the class of cryptogamia, and order of algæ. The fructification is inclosed in a diaphanous membrane. There are 17 species; 12 of which are British plants.
They are all sessile, and without roots, and grow in ditches and on stones along the sea-coast. None of them are applied to any particular use different from the rest of the algae, except perhaps the umbilicalis, which in England is pickled with salt and preserved in jars, and afterwards stewed and eaten with oil and lemon-juice. This species, called in English the navel laver, is flat, orbicular, tessile, and coraceous.