Description from Flora of China
Herbs, shrubs, or climbers, rarely trees, usually aromatic. Vascular bundles ± scattered in transverse section in a monocotyledonlike manner. Tip of stem sometimes enclosed within a stipulelike sheath, the prophyll, sometimes adnate to petiole, absent in Peperomia. Leaves alternate, often opposite or whorled in Peperomia, simple, base often asymmetric, palmately or pinnately veined. Inflorescence a pedunculate spike, rarely grouped into an umbel, rarely a raceme (in Zippelia), leaf-opposed or axillary, rarely terminal. Flowers small, bisexual, hermaphroditic, polygamous or dioecious, nearly always sessile; bracts small, usually peltate or cupular, usually without perianth. Stamens 1-10; filaments usually free; anthers 2-locular, distinct or connate, longitudinally dehiscent. Gynoecium 2-5-carpellate, connate; ovary superior, 1-locular, ovule 1, orthotropous; stigmas 1-5, sessile or with very short styles. Fruit a small drupe or nutlet; pericarp fleshy, thin or dry, sometimes with sticky papillae (in Peperomia) or glochidiate spines (in Zippelia). Seeds with copious starchy perisperm and a minute embryo embedded in small endosperm.
About eight or nine genera and 2000-3000 species: tropical and subtropical regions, mostly in North and South America, rather fewer in Asia, a few in Africa; three genera and 68 species (36 endemic, four introduced) in China.
Chinese species of economic value include Peperomia blanda, P. tetraphylla (medicines), Piper hainanense, P. hancei, P. hongkongense, P. nigrum (spice, medicine), P. sarmentosum, P. wallichii, P. wangii, and P. yunnanense.
Tseng Yung-chien, Chen Pei-shan & Zhu Pei-zhi. 1982. Piperaceae. In: Tseng Yung-chien, ed., Fl. Reipubl. Popularis Sin. 20(1): 11-78.
(Authors: Cheng Yongqian (程用谦 Tseng Yung-chien) , Xia Nianhe (夏念和)1; Michael G. Gilbert)