DCHP-1 Online
nigger wool 
n. a coarse grass or sedge, Carex filifolia, of the prairies, used widely in mulching to combat soil erosion.
See also: prairie wool
- 1952 The characteristic species of the short grass are: June grass . . . blue grama . . . nigger wool. . . .
- 1952 The characteristic species of the short grass are: June grass . . . blue grama . . . nigger wool. . . .