Zhen Zhu Cao

Zhen Zhu Cao (珍珠草), or pearl-grass, is Phyllanthus urinaria L., a small annual herb in the Phyllanthaceae (formerly Euphorbiaceae) widespread across tropical and subtropical Asia. The plant grows 10–60 cm tall with slender, often reddish, ribbed stems bearing two ranks of small oblong leaflets that close at night, giving a fern-like appearance. Tiny apetalous unisexual flowers and minute warty capsular fruits sit beneath the leaf axils in two neat rows along the underside of the branchlets, resembling rows of pearls. The whole plant is collected in summer and autumn, washed, and dried for medicinal use; it is widely employed in southern China and across Southeast Asia for liver and urinary conditions.