Du Zhong

Cortex Eucommiae (Duzhong) Eucommia Bark Eucommia Bark is the dried stem bark of Eucommia ulmoides Oliv. (Fam. Eucommiaceae). The drug is collected from April to June, removed from the coarse bark, piled up until the inner surface becomes purplish-brown, and dried in the sun. Description Flat pieces, or two edges somewhat curved inwards, varying in size, 3-7 mm thick. Outer surface pale brown or greyish-brown, markedly wrinkled or fissured and channelled longitudinally; some barks relatively thin, showing distinct lenticels when the coarse bark unscraped; inner surface dark purple, smooth. Texture fragile, easily broken, fracture linked up by fine, dense, silvery and elastic rubber threads. Odour, slight; taste, slightly bitter. Identification (1) Powder: Brown. Rubber threads stripe-shaped or twisted into masses, surface granular. Stone cells numerous, mostly in groups, subrectangular, subrounded, elongated-rectangular or irregular, 20-80 mm in diameter, up to 180 mm long, thick-walle