''Chrozophora tinctoria'' (commonly known as dyer's croton, giradol,

turnsole Turnsole, katasol, or folium was a dyestuff prepared from the annual plant ''Chrozophora tinctoria''. History Turnsole became a mainstay of medieval Illuminated manuscript, manuscript illuminators starting with the development of the technique fo ...

or dyer's litmus plant) is a plant species native to the

Mediterranean The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern ...

, the

Middle East The Middle East (term originally coined in English language) is a geopolitical region encompassing the Arabian Peninsula, the Levant, Turkey, Egypt, Iran, and Iraq. The term came into widespread usage by the United Kingdom and western Eur ...

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

Pakistan Pakistan, officially the Islamic Republic of Pakistan, is a country in South Asia. It is the List of countries and dependencies by population, fifth-most populous country, with a population of over 241.5 million, having the Islam by country# ...

, and

Central Asia Central Asia is a region of Asia consisting of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. The countries as a group are also colloquially referred to as the "-stans" as all have names ending with the Persian language, Pers ...

.Kew World Checklist of Selected Plant Families
/ref> It is also present as a weed in North America and Australia.

Description

It is an annual, typically found in nutrient-poor ground. It develops a large

taproot A taproot is a large, central, and dominant root from which other roots sprout laterally. Typically a taproot is somewhat straight and very thick, is tapering in shape, and grows directly downward. In some plants, such as the carrot, the taproot ...

. The plant is erect and covered with wool-like hairs. The ash-green leaves are alternate. The tiny monecious flowers are grouped in a

raceme A raceme () or racemoid is an unbranched, indeterminate growth, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are ...

. The lower, female flowers lack petals and the upper male flowers have five small yellow petals. Pollination is by ants. The fruits are conspicuous and consist of three dark green conjoined spheres. Their surface is decorated with white scales and warty structures. Each sphere contains three seeds, which are propelled away from the plant by the mechanical force of the mature fruit twisting as it opens. It is considered a poisonous plant. Its consumption may cause stomach upset, vomiting, nausea, and diarrhoea.

Use for dye

''Chrozophora tinctoria'' produced the blue-purple colorant "

" (also known as katasol or folium ) used in medieval

illuminated manuscript An illuminated manuscript is a formally prepared manuscript, document where the text is decorated with flourishes such as marginalia, borders and Miniature (illuminated manuscript), miniature illustrations. Often used in the Roman Catholic Churc ...

s and as a food colorant in Dutch cheese and certain liquors. Its use was mostly as substitute of the more expensive Tyrian purple, the famous dye obtained from Murex molluscs.M. Aceto, E. Calà, A. Agostino, G. Fenoglio, A. Idone, C. Porte, M. Gulmini, On the identification of folium and orchil on illuminated manuscripts, Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, http://dx.doi.org/10.1016/j.saa.2016.08.046 The color comes from the plant's fruit, specifically its dry outer coat. The colorant is also obtained from the translucent sap contained in the plant cells when the leaves of the plant are broken off and exposed to the air., s.v. ''Chrozophora tinctoria'' Different shades of blue and purple may also be obtained when the juice extracts are exposed to the vapors emitted from

ammonia Ammonia is an inorganic chemical compound of nitrogen and hydrogen with the chemical formula, formula . A Binary compounds of hydrogen, stable binary hydride and the simplest pnictogen hydride, ammonia is a colourless gas with a distinctive pu ...

(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. The plant has historically been used throughout the

Levant The Levant ( ) is the subregion that borders the Eastern Mediterranean, Eastern Mediterranean sea to the west, and forms the core of West Asia and the political term, Middle East, ''Middle East''. In its narrowest sense, which is in use toda ...

to dye clothing. of the plant produces of sap, and with this quantity one is able to dye of fabric rolls. In 2020, an interdisciplinary team of researchers from FCT NOVA,

University of Porto The University of Porto (''Universidade do Porto'') is a Portuguese public research university located in Porto, and founded on 22 March 1911. It is the second largest Portuguese university by number of enrolled students, after the University ...

and University of Aveiro, identified the complex chemical structure of the medieval purple-blue dye extracted from the fruits of ''Chrozophora tinctoria''. The chemical structure of the medieval dye was a mystery until now. The extracts obtained showed a novel blue chemical,

chrozophoridine Chrozophoridin is a chemical used as a dye. It is derived from the plant '' Chrozophora tinctoria'' (commonly known as dyer's croton, giradol, or turnsole), which is a species native to the Mediterranean, the Middle East, India, Pakistan, and Ce ...

as the main chromophore.

References

{{Taxonbar, from=Q1984236 Chrozophoreae Plants described in 1753 Taxa named by Carl Linnaeus Taxa named by Adrien-Henri de Jussieu Flora of Asia Plant dyes Flora of Malta