\▐kwәr-▐si-trәn, ▐kwәr-▐\ n [blend of NL Quercus and ISV citron] (1794) C15H10O7C21H20O12. (1) The inner part of a North American black oak tree (Quercus velutina), containing tannin and used in tanning and dyeing. (2) A yellow dye made from this bark. (3) Natural yellow matter obtained from the bark of Quercus nigra (oak) or Quercus tinctorial, and it is used primarily for the production of yellow lake pigments. The principal constituents are quercitrin and quercetin (Merriam-Webster’s Collegiate Dictionary, 11th Ed., Merriam-Webster, Inc., Springfield, Massachusetts, U.S.A., 2004).