Chrysanthemum cinerariifolium: A plant species of the genus CHRYSANTHEMUM, family ASTERACEAE. The flowers contain PYRETHRINS, cinerolones, and chrysanthemines which are powerful contact insecticides. Most in the old Pyrethrum genus are reclassified to TANACETUM; some to other ASTERACEAE genera.Chrysanthemum: A plant genus of the family ASTERACEAE. The common names of daisy or marguerite are easily confused with other plants. Some species in this genus have been reclassified to TANACETUM.Trichomes: Hair-like extensions on specialized epidermal surfaces of plants which protect against damage from insects, animals, light degradation and fungal infection. Trichomes may also occur on certain unicellular EUKARYOTES.