Qian Jin Zi

Qian Jin Zi is the mature seed of Euphorbia lathyris L. (Euphorbiaceae), known as caper spurge or mole plant, a biennial herb 60-120 cm tall native to the Mediterranean and now widely naturalized in temperate China. The erect, glaucous, blue-green stem exudes a copious irritant white latex when broken. Sessile, opposite, lanceolate to linear leaves are arranged in decussate pairs, giving the plant a strikingly geometric appearance. Yellow-green cyathia held within paired heart-shaped bracts produce three-lobed capsules 8-15 mm wide; each capsule splits explosively to release three smooth, oval, brown seeds 5-6 mm long with reticulate testae. The seeds are processed (often de-fatted as Qian Jin Zi Shuang) before use and are classified as drastic purgatives that drive out water retention. They are highly toxic and irritant; modern practice limits internal use to processed seeds in carefully controlled small doses by trained practitioners only.