Illustrated Glossary of Organic Chemistry

Tartaric acid: Any one of the three stereoisomers of 2,3-dihydroxysuccinic acid.
(+)-(2R,3R)-tartaric acid,
a component of racemic acid.		   
(-)-(2S,3S)-tartaric acid,
a component of racemic acid.		   
(2R,3S)-tartaric acid
(mesotartaric acid)