An aldohexose sugar. In some plants, notably members of the Leguminosae, mannose rather than glucose is the monosaccharide building block for reserve polysaccharides: the polysaccharides formed are known as *mannans
. Mannose is also found as a component of some hemicelluloses. The reduction product of mannose, *mannitol
, is an important sugar in lichens and some algae.