turnsole

Any of various plants that move or are believed to move in response to the sun, especially the Mediterranean species Chrozophora tinctoria.

A plant of the genus Heliotropium; heliotrope; — so named because its flowers are supposed to turn toward the sun.

The sunflower.

A kind of spurge (Euphorbia Helioscopia).

The euphorbiaceous plant Chrozophora tinctoria.

Litmus.

A purple dye obtained from the plant turnsole. See def. 1 (d).