turnsole
/ˈtɜːnsəʊl/noun
1- a Mediterranean plant of the spurge family, whose flowers are said to turn with the sun（地中海的大戟科植物）向阳性植物; 染料沙戟。
1.1
- Chrozophora tinctoria (family Euphorbiaceae), from which a blue or purple dye was formerly obtained.拉丁名Chrozophora tinctoria（大戟科）, 原用来提取蓝色或紫色染料。
词源
late Middle English: from Old French tournesole, based on Latin tornare （see TURN） + sol 'sun'.