Tong Cao

Tetrapanax papyrifer (Hook.) K.Koch (Araliaceae), the rice-paper plant, is an evergreen shrub or small tree 1-5 m tall native to Taiwan and southern China, with stout pithy stems, large palmately 7-12-lobed leaves up to 50 cm across covered in stellate fuzz beneath, and large terminal panicles of small whitish flowers in dense globose umbels. The stems contain an abundant white cylindrical pith. For Tong Cao, two- to three-year-old stems are cut in autumn, the pith is pushed out as long white cylinders, sun-dried, and cut into segments or sheets (the source of traditional 'rice paper'). In TCM, Tong Cao is sweet and bland in flavor and slightly cold in nature, entering the Lung and Stomach channels; it promotes urination, clears damp-heat from the urinary bladder, and promotes lactation.