turnsole

 
Pronunciation: /ˈtəːnsəʊl/

noun

  • a Mediterranean plant of the spurge family, whose flowers are said to turn with the sun.
    • Chrozophora tinctoria (family Euphorbiaceae), from which a blue or purple dye was formerly obtained

Origin:

late Middle English: from Old French tournesole, based on Latin tornare (see turn) + sol 'sun'