A name given to the astringent roots of various plants.
1818. Nuttall, Gen. N. Amer. Plants, I. 174. Heuchera, Allum-root.
1830. Lindley, Nat. Syst. Bot., 140. The root of Geranium maculatum is considered a valuable astringent in North America, where it is sometimes called Alum root.
1866. Treas. Bot., 588. The root of Heuchera americana is so astringent that it is called Alum root.
