noun. 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.
- painted daisy
- Tanacetum coccineum
- Chrysanthemum coccineum
noun. white-flowered pyrethrum of Balkan area whose pinnate leaves are white and silky-hairy below; source of an insecticide; sometimes placed in genus Chrysanthemum.
- herbaceous plant
- Dalmatian pyrethrum
- Tanacetum cinerariifolium
- Chrysanthemum cinerariifolium
- Dalmatia pyrethrum
noun. used in former classifications for plants later placed in genus Chrysanthemum and now often included in genus Tanacetum.
- asterid dicot genus
- family Asteraceae
- genus Pyrethrum
- family Compositae
noun. made of dried flower heads of pyrethrum plants.
- insect powder
Example sentences of the word pyrethrum
1. Noun, singular or mass
The most effective weapon in killing the lily beetles and its hungry offspring is Pyrethrum spray, which is an organic pesticide made from the pyrethrum flower.
Dilute 1/4 to 1/2 fluid ounces of a pyrethrum insecticide concentrate in 1 gallon of water.