A perennial herb(Rumex hymenosepalus) native chiefly to southwest North America, having tannin-rich, tuberous roots formerly used for tanning and in herbal medicine.

• 膜萼酸模：一种主要原产于北美洲西南部的多年生草本植物（膜萼酸模酸模属），长有富含鞣质的块状根，以前用于制革和草药