ding! Chrysanthemum. Sidenote: pyrethrum is the natural deriviative of the flower, pyrethroids are synthetic based on pyrethrum (permethrin).
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Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, a critter that can be killed but can't be tamed. --Robert A. Heinlein