apetalousyoudaoicibaDictYouDict[apetalous 词源字典]
"(Of a flower) having no petals", Early 18th century: from modern Latin apetalus, from Greek apetalos 'leafless' (from a- 'without' + petalon 'leaf') + -ous.[apetalous etymology, apetalous origin, 英语词源]