Martindale, 25th Edn., p.617. Merck Index, 7th Edn., P. 189. The unpeeled drug is covered in a thin brown cork and is much shrunken and deeply wrinkled longitudinally. It bears on the upper surface triangular leaf scars and hairlike fibres of fibrovascular tissue, and on the under surface many small root scars. The peeled drug is cream-yellow in colour and exhibits fewer root scars.
Calamus breaks with a sharp fracture producing a granular, white, spongy surface internally.
The section has a large stele separated by a yellowish line from the cortex. Both the stele and cortex are covered with small oval fibrovascular bundles. A few xylem elements are present usually in the form of groups of vessels with annular or reticulate thickening. It may be used with Althaea and Filipendula in gastric inflammation. Dose 1-3 g or by infusion.