turnsole

noun6

1. •
   A heliotrope; so named because its flowers are supposed to turn toward the sun.
2. •
   A sunflower.
3. •
   A sun spurge (Euphorbia helioscopia).
4. •
   The euphorbiaceous plant Chrozophora tinctoria.
5. •
   A purple dye obtained from Chrozophora tinctoria.
6. •
   (no longer used) litmus