py·re·thrum /paɪˈriθrəm, ˈrɛ-/
  除蟲菊
  py·re·thrum /paɪˈrɪθrəm, ˈrɛθrəm/ 名詞
  pyrethrum
       n 1: made of dried flower heads of pyrethrum plants
       2: white-flowered pyrethrum of Balkan area whose pinnate leaves
          are white and silky-hairy below; source of an insecticide;
          sometimes placed in genus Chrysanthemum [syn: Dalmatian
          pyrethrum, Dalmatia pyrethrum, Tanacetum
          cinerariifolium, Chrysanthemum cinerariifolium]
       3: spring-flowering garden perennial of Asiatic origin having
          finely divided aromatic leaves and white to pink-purple
          flowers; source of an insecticide; sometimes placed in
          genus Chrysanthemum [syn: painted daisy, Tanacetum
          coccineum, Chrysanthemum coccineum]
       4: used in former classifications for plants later placed in
          genus Chrysanthemum and now often included in genus
          Tanacetum [syn: genus Pyrethrum]