1, rhizome difference: Acorus calamus rhizome is slightly flat, yellowish brown, fleshy, cattail root is milky white, and the aboveground stems are stout.

2, the difference between leaves: Acorus calamus leaves are flat and wide, light green, bright, long and thin, dark green, semi-oval, smooth.

The difference of flowers: Acorus calamus spikes are erect or oblique, cylindrical, yellow-green, Typha flowers are unisexual, and spikes are long and narrow.

4. Difference in fragrance: The fragrance of Acorus calamus and cattail is different. Acorus calamus has fragrance, while cattail has no fragrance.