butterwortyoudaoicibaDictYouDict[butterwort 词源字典]
"A carnivorous bog plant which has violet flowers borne above a rosette of greasy yellowish-green leaves that trap and digest small insects, found in both Eurasia and North America", Late 16th century: named from the plant's supposed ability to keep cows in milk, and so maintain the supply of butter.[butterwort etymology, butterwort origin, 英语词源]