canaigre

noun2

1. •
   (US) Rumex hymenosepalus, a species of dock native to southwestern North America with edible red stems and taproots containing tannin.

   • The true tannic acids are also widely distributed; […] in roots, as in the Texas plant, a Rumex commonly known as "Cañaigre;" […] — 1879
2. •
   (US) Tannin-containing matter obtained from the taproots of the plant.

   • Futhermore, other vegetable tannins, such as ground Canigre, Quebracho, Babul bark, Mimosa tannin and pure tannic acid are found to have a similar virucidal effect and are as acerin not bactericidal. — 1954