black moss

black moss (usually uncountable, plural black mosses)

1. Any of numerous species of dark-coloured mosses (Bryophyta), possibly species of the genera Grimmia, Andreaea, Syntrichia, Cinclidotus.
   • 1823, Agriculture, article in (editor), Encyclopaedia Britannica, 6th Edition, Volume 1, page 373,

     There are, however, two general kinds of mosses; black moss, and whitish or yellow moss. The black moss is originally of a mahogany colour, but speedily becomes black upon exposure to the air.

2. Tillandsia usneoides (Spanish moss), a flowering plant, particularly after it has been dried for use as stuffing and decoration.
3. Nostoc flagelliforme (fat choy), a terrestrial cyanobacterium eaten in Chinese cuisine.
   • 1999, Grace Young, The Wisdom of the Chinese Kitchen: Classic Family Recipes for Celebration and Healing‎, page 126:

     Black moss, also known as seaweed hair, looks like fine black hair. The name of the ingredient in Cantonese, fat choy, is the same as the New Year's greeting, Gung Hay Fat Choy, so it has an auspicious meaning and symbolizes prosperity.

4. (US) Bryoria fremontii (wila), a lichen eaten by First Peoples in North America.