pyrethrum(redirected from pyrethrums)
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a. A Eurasian perennial plant (Tanacetum coccineum) in the composite family, cultivated for its colorful flower heads and formerly used as a source of an insecticide. Also called painted daisy.
b. A closely related perennial plant (Tanacetum cinerariifolium), commercially cultivated as the source of an insecticide.
2. An insecticide made from the dried flower heads of any of these plants.
[Latin, pellitory (Anacyclus pyrethrum), from Greek purethron, from pūr, fire (from its warming effect); see pyretic.]
1. (Plants) any of several cultivated Eurasian chrysanthemums, such as Chrysanthemum coccineum and C. roseum, with white, pink, red, or purple flowers
2. (Elements & Compounds) any insecticide prepared from the dried flowers of any of these plants, esp C. roseum
[C16: via Latin from Greek purethron feverfew, probably from puretos fever; see pyretic]
py•re•thrum(paɪˈri θrəm, -ˈrɛθ rəm)
n., pl. -thrums, -thrum.
1. any of several chrysanthemums, as Chrysanthemum coccineum, having finely divided leaves and showy red, pink, lilac, or white flowers.
2. the dried flower heads of some of these plants, used as an insecticide and in medicine for certain skin disorders.
[1555–65; < Latin: pellitory]
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|Noun||1.||pyrethrum - made of dried flower heads of pyrethrum plants|
|2.||pyrethrum - white-flowered pyrethrum of Balkan area whose pinnate leaves are white and silky-hairy below; source of an insecticide; sometimes placed in genus Chrysanthemum|
genus Tanacetum, Tanacetum - a large genus of plants resembling chrysanthemums; comprises some plants often included in other genera especially genus Chrysanthemum
|3.||pyrethrum - 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|
flower - a plant cultivated for its blooms or blossoms
|4.||Pyrethrum - used in former classifications for plants later placed in genus Chrysanthemum and now often included in genus Tanacetum|
asterid dicot genus - genus of more or less advanced dicotyledonous herbs and some trees and shrubs