''Reseda luteola'' is a flowering plant species in the family Resedaceae. Common names include dyer's rocket, dyer's weed, weld, woold, and yellow weed. A native of Europe and Western Asia, the plant can be found in North America as an introduced species and common weed. While other resedas were used for the purpose, this species was the most widely used source of the natural dye known as weld. The plant is rich in luteolin, a

flavonoid Flavonoids (or bioflavonoids; from the Latin word ''flavus'', meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans. Chemically, flavonoids ...

which produces a bright yellow

dye A dye is a colored substance that chemically bonds to the substrate to which it is being applied. This distinguishes dyes from pigments which do not chemically bind to the material they color. Dye is generally applied in an aqueous solution an ...

.Flora of North America
/ref> The yellow could be mixed with the blue from woad (''Isatis tinctoria'') to produce greens such as Lincoln green.

History and usage

The dye was in use by the first millennium BC, and perhaps earlier than either woad or

madder ''Rubia'' is the type genus of the Rubiaceae family of flowering plants, which also contains coffee. It contains around 80 species of perennial scrambling or climbing herbs and subshrubs native to the Old World. The genus and its best-known spe ...

. Until the discovery of

quercitron Quercitron is a yellow natural dye obtained from the bark of the Eastern Black Oak (''Quercus velutina''), a forest tree indigenous in North America. It was formerly called Dutch pink, English pink, or Italian pink. The name is a shortened fo ...

it was the most used yellow dye but by the end of the 19th century had ceased to be in wide use due to the discovery of the synthetic aniline dyes which were cheaper to produce. Historically, France exported large quantities of weld. It prefers waste places. Good weld for dye must have flowers of a yellow or greenish color, and abound in leaves; that which is small, thin-stemmed, and yellow is better than that which is large, thick-stemmed, and green; that which grows on dry, sandy soils is better than that produced on rich and moist soils. For the greatest production of coloring matter, the plant should be cut before the fruits show much development, otherwise the pigment diminishes. Dye from weld serves equally for

linen Linen () is a textile made from the fibers of the flax plant. Linen is very strong, absorbent, and dries faster than cotton. Because of these properties, linen is comfortable to wear in hot weather and is valued for use in garments. It also ...

, wool, and silk, dyeing with proper management all shades of yellow, and producing a bright and beautiful color. Reseda is a primary dye for the wool tapestries at the

Ramses Wissa Wassef Art Centre Ramesses may refer to: Ancient Egypt Pharaohs of the nineteenth dynasty * Ramesses I, founder of the 19th Dynasty * Ramesses II, also called "Ramesses the Great" ** Prince Ramesses (prince), second son of Ramesses II ** Prince Ramesses-Merya ...

in Giza, Egypt. Each February, the reseda is harvested for the annual wool dyeing event among all the artists at the centre.

Natural chemical constituents

A dominating natural plant chemical in ''Reseda luteola'' is glucobarbarin, named for its occurrence in a distantly related plant, '' Barbarea vulgaris''. Glucobarbarin is a

glucosinolate Glucosinolates are natural components of many pungent plants such as mustard, cabbage, and horseradish. The pungency of those plants is due to mustard oils produced from glucosinolates when the plant material is chewed, cut, or otherwise damaged. T ...

, the characteristic chemicals in the order Brassicales (Cabbages, mustards etc.) that ''Reseda luteola'' belongs to. When the plant is crushed, glucobarbarin is converted by an enzyme int
barbarin
(5-phenyl-1,3-oxazolidine-2-thione). This compound is sometimes (inappropriately) named resedinine, a name coined by Soviet researchers that rediscovered the compound in ''Reseda luteola'' (Lutfullin et al., 1976) apparently without being aware of the previous discovery and naming in the west around two decades earlier. Yet another enzyme slowly converts barbarin into resedine (5-phenyl-1,3-oxazolidin-2-one), this chemical discovered and named by the same Soviet researchers (Lutfullin et al., 1976), giving it a name that is still valid. Barbarin and resedine can also be called alkaloids, but they are not typical alkaloids, in that they do not exist in the intact plant but are only formed after crushing the plant physically. Glucobarbarin, like other

s, is known to attract cabbage butterflies for egg-laying. Any ecological, medical or health effects of barbarin and resedine are poorly understood. File:3- Reseda leaves for Yellow.jpg, Ramses Wissa Wassef Art Centre annual wool dyeing with reseda File:Wool Dyed with Reseda. (1).jpg, Wool dyed with reseda at Wissa Wassef Art Centre, Giza, Egypt, 2016

References

*Lutfullin, KL, Tadzhibaev MM, Abdullaev UA, Malikov VM, Yunusov SY, 1976. Alkaloids of ''Reseda luteola''. ''Khimya Prir. Soedin.'' 5, 625-630 (In Russian).

External links

Jepson Manual TreatmentWashington Burke MuseumPhoto gallery
{{Taxonbar, from=Q157927 luteola Plant dyes Plants described in 1753 Taxa named by Carl Linnaeus