Blue grass \Blue" grass`\ (Bot.) A species of grass (Poa compressa) with bluish green stems, valuable in thin gravelly soils; wire grass.

Kentucky blue grass, a species of grass (Poa pratensis) which has running rootstocks and spreads rapidly. It is valuable as a pasture grass, as it endures both winter and drought better than other kinds, and is very nutritious.

Source: Webster's Revised Unabridged Dictionary (1913)