pyrethrum

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py·re·thrum

 (pī-rē′thrəm, -rĕth′rəm)
n.
1.
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.]

pyrethrum

(paɪˈriːθrəm)
n
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]
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.pyrethrum - made of dried flower heads of pyrethrum plants
insect powder, insecticide - a chemical used to kill insects
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
herb, herbaceous plant - a plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests
3.pyrethrum - spring-flowering garden perennial of Asiatic origin having finely divided aromatic leaves and white to pink-purple flowerspyrethrum - 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
genus Tanacetum, Tanacetum - a large genus of plants resembling chrysanthemums; comprises some plants often included in other genera especially genus Chrysanthemum
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
aster family, Asteraceae, Compositae, family Asteraceae, family Compositae - plants with heads composed of many florets: aster; daisy; dandelion; goldenrod; marigold; lettuces; ragweed; sunflower; thistle; zinnia
Translations

pyrethrum

[paɪˈriːθrəm] Npiretro m
References in periodicals archive ?
Experimental fields, reported Clay, are testing the efficiency of pyrethrums as part of an integrated pest management strategy.
Although you can no longer buy Derris after it was linked to Parkinson's disease, there are plenty of organic pesticides based on plant oils and pyrethrums.
This initiative has led to the use of environmentally friendly insecticides that can undergo biodegradation and have minimal impact on the environment such as pyrethrums and pyrethroids.
Roses, gerberas and pyrethrums are especially prone to this problem.