sunflower (n.)youdaoicibaDictYouDict[sunflower 词源字典]
1560s, "heliotrope," from sun (n.) + flower (n.). In reference to the Helianthus (introduced to Europe 1510 from America by the Spaniards) it is attested from 1590s, so called from the appearance of the heads.[sunflower etymology, sunflower origin, 英语词源]