Chrozophora tinctoria (commonly known as dyer's croton,[2] giradol,[2] turnsole[2] or dyer's litmus plant[3]) is a plant species native to the Mediterranean, the Middle East, India, Pakistan, and Central Asia.

Each sphere contains three seeds, which are propelled away from the plant by the mechanical force of the mature fruit twisting as it opens.

[11] Its use was mostly as substitute of the more expensive Tyrian purple, the famous dye obtained from Murex molluscs.

[13] Different shades of blue and purple may also be obtained when the juice extracts are exposed to the vapors emitted from ammonia (NH3), and which in France, during the late 19th century, was produced by applying fresh horse manure and urine to the fabric that was soaked with the plant extract.

[13] In 2020, an interdisciplinary team of researchers from FCT NOVA, University of Porto and University of Aveiro, identified the complex chemical structure of the medieval purple-blue dye extracted from the fruits of Chrozophora tinctoria.