turnsole

Modern traditions substitute the turnsole with a sunflower, which is also known for turning in the direction of the sun.

The Middle English name "turnsole" has the same meaning.

Turnsole or folium was a dyestuff prepared from the annual plant Chrozophora tinctoria.

At another table, two women were re-feathering roasted peacocks with feathers colored by saffron and yellow turnsole.

Indian turnsole (English)

C. tinctoria produced the blue-purple colorant "turnsole" used in medieval illuminated manuscripts and as a food colorant.

Chrozophora tinctoria (commonly known as dyer's croton, giradol, or turnsole) is the type species in the genus Chrozophora.

Heliotropium europaeum is a species of heliotrope known by the common names European Heliotrope and European Turnsole.

Heliotropium europaeum - European Heliotrope, European Turnsole (Europe, Asia, and North Africa)

The French Cook by François Pierre La Varenne (London 1653) mentions turnsole grated in water with a little powder of Iris.

After nine days she was transformed into the turnsole (which is known for growing on sunny, rocky hillsides), which turns its head always to look longingly at Helios' chariot of the sun.

Turnsole became a mainstay of medieval manuscript illuminators starting with the development of the technique for extracting it in the thirteenth century, when it joined the vegetable-based woad and indigo in the illuminator's repertory.

According to its method of preparation, turnsole produced a range of translucent colors from blue, through purple to red, according to its reaction to the acidity or alkalinity of its environment, in the chemical reaction, not understood in the Middle Ages, that is most familiar in the Litmus test.

In the early fifteenth century, Cennino Cennini, in his Libro dell' Arte gives a recipe "LXVIII: How you should tint paper turnsole color" and "LXXVI To paint a purple or turnsole drapery in fresco."