The plant Kalmegh or Creat commonly grows as wild in shady places, waste lands and roadsides. The plant belongs to the family Acanthaceae. It is an erect annual branched herb with quadrangular stem. Leaves simple, glabrous, lanceolate, dark green. Flowers rose-purple in axillary and terminal panicled racemes. Fruit linear-oblong capsule. The peculiar character of the plant is its bitterness which represents the quality of the material. Andrographolides, a furanoid diterpenes are the active compounds of the plant.
The plant is considered as anthelmintic, antifebrile, anodyne, astringent and antidysenteric. It is considered to be good in jaundice, liver troubles, intermittent and remittent fevers. The plant and its preparation are also considered to be a good blood purifier.