Wang Bu Liu Xing

Vaccaria hispanica (Mill.) Rauschert (syn. V. segetalis, V. pyramidata; Caryophyllaceae), known as cowherb or cow soapwort, is a slender annual herb 30-80 cm tall with smooth, glaucous, dichotomously branched stems. The opposite, sessile, lanceolate to ovate leaves are entire and somewhat clasping. Loose, terminal cymes carry pink, five-petaled flowers about 1.5 cm across, subtended by an inflated, five-angled calyx that persists around the fruit. The capsule contains numerous small, globose, blackish seeds (Wang Bu Liu Xing). A weed of cultivated grain fields in temperate Eurasia, the plant has naturalized widely; only the dried ripe seed is used medicinally in traditional Chinese practice to invigorate blood circulation, unblock the channels, promote lactation, and reduce swelling.