Calamus (Acorus calamus) – this is perennial grassy plant. Stem vertical, branchless, 60-100 cm high, from one size – furrowy, from other side – with sharp edge, near the basis – reddish, usually light viotel tinge. All plant parts, especially rootstock, are strong flavour breath. Calamus rootstoch contains volatile oil, starch, sour substances, ascorbic acid. Leaves also have volatile oil and some sour substances.