Imperata, the sweet root of refreshing herbal teas

Bai Mao Gen means “the root of the white mao”: its leaves are tapered like spearheads, and the character for mao contains precisely that for spear, while its flower and root are white. It is the slender, jointed rhizome of a perennial grass, imperata (cogongrass), which grows wild throughout China and is not cultivated. China counts it among the substances that are both food and pharmacopoeia herb, and the South makes it one of the ingredients of its refreshing herbal teas. The quality criterion comes down to three words: thick stems, white colour, sweet taste. It is harvested in spring and autumn, never in summer, as it then loses its sugar.

Clearing Heat without drying

In Traditional Chinese Medicine, imperata is cold and sweet, and its whole character lies in this combination. Cold clears Heat; sweetness spares the Stomach and the Fluids, which bitter, cold substances wear down. It enters the Lung and the Stomach, whose Heat it clears, and it cools the Blood without drying it or making it sticky. Sweet and juicy, it generates Fluids while it clears: the fresh root, chewed, gives a lot of juice. Li Shizhen defended it against those who scorned it because it seems unimportant: “it is truly a good substance”.

Guiding Heat downwards

Through its third meridian, the Bladder, the root guides Heat downwards and lets it out through the waterways: tradition says it makes urine flow. It is often compared with reed rhizome, another sweet, cold grass with similar uses: reed works at the Qi level, imperata at the Blood level, and together they cover both levels without drying. Reed rhizome is recognisable by its thickness and hollow centre; imperata is slender, solid and sweet.