A sweet-smelling cane plant (Exodus 30:23; Ezekiel 27:19). Calamus refers to either a plant or its aromatic root. It was one of the plants that grew in Solomon's garden (Song of Solomon 4:14).
Two plants have been suggested as the source of biblical calamus:
the sweet flag (Acorus calamus), and
the beardgrass (Andropogon aromaticus).
The sweet flag has a strong pleasant smell and grows in Europe and Asia, but it is not found in Israel and the surrounding areas. Beardgrass, which comes from India, releases a strong fragrance when crushed and is thought to be the calamus mentioned in the Bible. Beardgrass produces an oil called ginger-grass oil.