Long Dan Rhizomes irregularly lump-shaped, 1-3 cm long, 0.3-1 cm in diameter; externally dark greyish-brown or dark brown, the upper part with stem scars or remains of stem bases, surrounding and the lower part bearing numerous slender roots. Roots cylindrical, slightly twisted, 10-20 cm long, 2-5 mm in diameter; externally pale yellow or yellowish-brown, mostly the upper part exhibiting obvious transverse wrinkles, the lower part narrower and marked with longitudinal wrinkles and rootlet scars. Texture fragile, easily broken, fracture slightly even, bark yellowish-white or yellowish-brown, wood paler in colour and appearing dotted-ringed. Odour, slight; taste, rather bitter.

Jaundice caused by damp-heat; swelling and itching of the vulva with excessive leucorrhea; prolonged erection of the penis with spontaneous emission; eczema accompanied with itching; blood-shot eyes, impairment of hearing, pain in the costal regions and bitter taste in the mouth, convulsion.

1.Reducing heat and resolving damphess:

The drug is one of the medicines frequently used for eliminating damp-heat from the liver, gall bladder and lower Jiao. For the treatment of jaundice due to damp-heat, it can be combined with Herba Artemisiae Scopariae, Radix Curcumae, Cortex Phellodendri, etc.; for the treatment of pruritus of the vulvae or scrotum due to the decending of damp-heat, with Semen Plantaginis, Talcum, etc. which are medicines for eliminating damp-heat.

2.Eliminating intense fire from the liver:

For the treatment of asthenia-fire syndrome of the liver and gall bladder, marked by headache and feeling of destention in the head, bloodshot eyes, deafness and swelling of the ears, hypochondriac pain and bitterness of the mouth, etc., it is often combined with Radix Scutellariae, Fructus Gardeniae, etc.; for the treatment of persistent high fever accompanied with convulsion due to stirring of wind caused by liver-heat, with drugs for eliminating liver heat such as Concha Haliotidis, Aloe, Ramulus Uncariae cum Uncis.