Quercitron

The dyestuff is prepared by grinding the bark in mills after it has been freed from its black epidermal layer, and sifting the product to separate the fibrous matter, the fine yellow powder which remains forming the quercitron of commerce.

Either by itself or in some form of its glucoside quercitrin, quercetin is found in several vegetable substances, among others in cutch, in Persian berries (Rhamnus cathartica), buckwheat leaves (Fagopyrum esculentum), Zante fustic wood (Rhus cotinus), and in rose petals.

[2] Chemically, quercetin is a member of a fairly extensive class of natural coloring matters derived from phenyl benzoyl-pyrone or flavone, the constitution of which followed on the researches of Stanisław Kostanecki, A. G. Perkin, Herzig, Goldschmidt and others.

Among the related, coloring matters are: chrysin from poplar buds, apigenin from parsley, luteolin from weld, mignonette and dyer's broom, fisetin from young fustic and yellow cypress, galangin from galangal root, and myricetin from Nageia nagi.

[2] In Iowa in the late 1840s and early 1850s, according to the historian Philip Dillon Jordan: Weld, fustic, and quercitron bark were carried as staple items in drug stores and general merchandise establishments.