Folium Isatidis
Dyers Woad Leaf

Source:
The leaf of Isatis indigotica Fort. (Fam. Cruciferae).

Distribution:
Mainly in Chinese provinces such as Hebei, Shaanxi, Jiangsu and Anhui.

Harvest & Processing
Collect leaves in different rounds in summer and autumn; remove foreign matter; dry under the sun.

Description:
Leaves mostly shrivelled and in fragments; when intact, blades oblong and elliptical to oblong, orbicular (round) and oblanceolate (inverse lance-head shaped); 4-16 cm long, 1-4 cm wide. Apex blunt but slightly pointed or obtuse; base attenuate (tapering gradually to a narrow tip or base) and decurrent (extending downwards), forming an aliform (wing-shaped) petiole; margin entire (continuous and even) or slightly undulate (wavy); upper surface and underside greyish-green or brownish-green, glabrous (without hairs), with pinnate (feather-shaped), reticulate (netlike) veins; main vein protuberant on underside. Brittle. Odour: faint; taste: slightly bitter.

Indications:
1. Seasonal febrile diseases, pestilence
2. Influenza, epidemic meningitis, encephalitis B, viral pneumonia, mumps and other eruptive exanthem
3. Sore throat, aphthous ulcer

Chemical Composition:
Contains indigo, indigotin, isatan B and indirubin.