Somewhat cylindrical, with 2-3 or more branches at the lower part, 10-30cm long. Root stock enlarged, conical, with abundant transverse wrinkles, 1.5-3cm in diameter, apex exhibiting remains of stems and leaves or sunken spots. Externally greyish-brown or dark brown, longitudinally wrinkled, with prominent, transverse lenticels and slightly prominent scars of rootlet. Texture relatively hard, soft when moistened; fracture showing bark greyish-white, scattered with abundant brown oil cavities, wood greyish-yellow to yellowish-brown, and cambium ring brown. Odour, characteristic and aromatic; taste, bitter and pungent, slightly numb.

Purpura dark in colour due to presence of exuberant toxic heat in blood; measles with inadequate eruption; sores; eczema; scalds and burns.

1.Dispelling wind, resolving dampness and relieving pain

To treat arthralgia due to wind and dampness, with heaviness of lumbar regions and lower limbs, it is often used with Ramulus Loranthi, Radix Gentianae Macrophyllae, Radix Achyranthis Bidentatae, etc. The drug can produce the effect of treating wind in the interior of the lower portion of the human body, so it is suitable to be used in treating arthralgia of the muscles and joints in the lower portion.

2. Dispelling cold by perspiration

To treat cold due to wind-cold with headache and general soreness, it may be used with Rhizoma seu Radix Notopterygii, Radix Ledebouriellae, Radix Angelicae Dahuricae, Rhizoma Ligustici Chuanxiong, Radix Glycyrrhizae, Rhizoma Zingiberis Recens, etc.