Chu Shi Zi

Broussonetia papyrifera, the paper mulberry, is a fast-growing deciduous tree of the family Moraceae, native to East Asia and widely naturalized, often invasively, across the Pacific and southeastern North America. It reaches 10 to 15 meters with smooth gray bark and abundant milky sap. The leaves are notably variable, even on the same plant, ranging from simple ovate-cordate with serrate margins to deeply two- or three-lobed, all rough above and softly pubescent beneath. The species is dioecious; male trees bear pendulous catkins and female trees produce globose, bright orange to red compound infructescences 2 to 3 cm across in summer, composed of numerous fleshy, protruding individual drupelets with conspicuous styles. These soft, sweet fruits, harvested when fully ripe, are the medicinal Chu Shi Zi.