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.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

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]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

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]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
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
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
Translations

pyrethrum

[paɪˈriːθrəm] Npiretro m
Collins Spanish Dictionary - Complete and Unabridged 8th Edition 2005 © William Collins Sons & Co. Ltd. 1971, 1988 © HarperCollins Publishers 1992, 1993, 1996, 1997, 2000, 2003, 2005
References in periodicals archive ?
'In the last financial year we were able to revive tea, cotton, pyrethrum, sisal and coffee farming," the governor said.
Nakuru is the leading producer of potatoes, carrots, milk, vegetables and pyrethrum. Molo, Subukia, Kuresoi South and North and Njoro are among agriculturally rich areas in the county.
Five insecticides were used in the experiment: (1) Confidor (17.8% imidacloprid, Bayer East Africa, Nairobi, Kenya); (2) Fastac (10% alpha-cypermethrin, BASF Corporation, Nairobi sub-office; Nairobi, Kenya); (3) Pyrethrum 5EW (5% pyrethrins, Agropy Ltd, Kigali, Rwanda; (4) Pyrethrum EWC (2.19% pyrethrins and 10% sesame, Agropy Ltd, Kigali, Rwanda); and (5) Agroblaster (8% pyrethrins, SOPYRWA, Musanze, Rwanda).
In his case study of pyrethrum farming (daisies from which an insecticidal compound is extracted), Huggins takes us back to 1963, when the Gregoire Kayibanda administration created pyrethrum farms from the Volcanoes National Park to produce one of Rwanda's key exports.
Add equal parts of two or three of the dried herbs listed above to dried pyrethrum flowers, and pulverize the herbs into a powder with a mortar and pestle or coffee grinder.
Pesticide-based remedies, the most common lice treatments, contain the active in gredients permethrin or pyrethrum, which are pesticides introduced more than four decades ago as pediculicides -- O-T-C drugs to kill lice.
The pyrethrum is then sprayed to the trees, after 10 minutes, the researchers will shake the trees and count the amount of antestia beetles that have been "knocked down" by the spray.
The chemicals -- pyrethrum, malathion and alpha- cypher are hazardous to health and large amounts of diesel sprayed at ' nose level' is a major cause of air pollution.
In particular, the Dalmatian chrysanthemum, or Tanacetum cinerariifolium, is an important source of the natural botanical insecticide, pyrethrum.
Infestations should be treated with the insecticide pyrethrum, which comes in various garden brands.
The plant Anacyclus pyrethrum (AP) consists of several N-alkylamides with pellitorine as main constituent.