quercitronyoudaoicibaDictYouDict[quercitron 词源字典]
"The inner bark of the American black oak, Quercus velutina, used as a source of the yellow dye quercitrin and in tanning (more fully quercitron bark)", Late 18th cent.; earliest use found in Statute 32 George III. Blend of quercine and citron adjective.[quercitron etymology, quercitron origin, 英语词源]