ULVA, LAVER, or Turkey Feather; a genus of the order of algae, belonging to the cryptogamia class of plants. It consists merely of a foliaceous substance formed into long cylindrical tubes. There are 10 species; of which the most remarkable are, 1. The umbilicalis, navel laver, in Scotland called stoke or slake, is frequent on sea-rocks, and sometimes on low shores, growing single. It is a wide membranaceous leaf, of a dark, dull, purple colour, expanded flat; for the most part in a circular form, variously sinuated on the edges; often perforated on the surface, and generally fixed to the rocks by a central root. The substance of it is smooth and shining, and a little tough, but not difficult to be torn. The breadth is from three inches to a foot. It often varies into a riband-like form. The inhabitants of the Western isles gather it in the month of March; and after pounding and stewing it with a little water, eat it with pepper, vinegar, and butter. Others stew it with leeks or onions. In England it is generally pickled with salt, and preserved in jars; and when brought to table is stewed, and eaten with oil and lemon-juice.