What is "alum root"

Alum root \Al"um root`\ (Bot.) A North American herb ( Heuchera Americana) of the Saxifrage family, whose root has astringent properties.

Alum root or Alumroot is a common name for some species of two different groups of plants:

• Heuchera - also called coralbells.
• Geranium - also called wild geranium or cranesbills.