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pyrethrum
py·re·thrum P0685800 (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) n1. (Plants) any of several cultivated Eurasian chrysanthemums, such as Chrysanthemum coccineum and C. roseum, with white, pink, red, or purple flowers2. (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] Thesaurus| Noun | 1. | pyrethrum - made of dried flower heads of pyrethrum plantsinsect 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 ChrysanthemumChrysanthemum cinerariifolium, Dalmatia pyrethrum, Dalmatian pyrethrum, Tanacetum cinerariifoliumgenus Tanacetum, Tanacetum - a large genus of plants resembling chrysanthemums; comprises some plants often included in other genera especially genus Chrysanthemumherb, 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 flowers; source of an insecticide; sometimes placed in genus ChrysanthemumChrysanthemum coccineum, painted daisy, Tanacetum coccineumflower - a plant cultivated for its blooms or blossomsgenus 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 Tanacetumgenus Pyrethrumasterid dicot genus - genus of more or less advanced dicotyledonous herbs and some trees and shrubsaster 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
pyrethrum (pīrē`thrəm): see chrysanthemumchrysanthemum
, name for a large number of annual or perennial herbs of the genus Chrysanthemum of the family Asteraceae (aster family), some cultivated in Asia for at least 2,000 years.
..... Click the link for more information. .Pyrethrum a genus of pubescent, perennial herbaceous plants of the family Compositae. The plants range in height from 5 to 150 cm. The alternate leaves are pinnatifid or, less frequently, entire. The small flowers are in heads, which are solitary or in two to 40 (less frequently, 100) corymbose inflorescences. The ray flowers are pistillate and ligulate, and the disk flowers are bisexual and tubular. There are about 100 species of Pyrethrum, distributed in Europe (except the Far North), Asia, and North Africa. The USSR has approximately 55 species, found mostly in southern and mountainous regions. Some species accumulate pyrethrins —substances that are poisonous to insects and other invertebrates. Two closely related species are cultivated: P. roseum (formerly P. carneum) and P. coccineum (formerly P. roseum). They grow in meadows and on the rocky slopes of the Caucasus, at elevations of 1,500 to 3,000 m. P. roseum, an herbaceous plant measuring 20 to 60 cm tall, has one or, less commonly, two or three flower heads. The leaves are not deeply pinnatifid, and the ray flowers are pink. The achenes, which are 2–3 mm long, are elongate and ribbed; they have a small crown. P. coccineum differs from P. roseum by its twice pinnatifid leaves. The ray flowers are pink or red. Both species contain substances in their inflorescences, stems, and leaves that have high insecticidal properties but are harmless to warm-blooded animals, including man. The Dalmatian pyrethrum (P. cinerariifolium) is cultivated as a source of insecticide. (It sometimes escapes cultivation.) The plant, which is native to the mountains of the Balkan Peninsula, is herbaceous and reaches a height of 15–45 cm. It has silvery gray twice or thrice pinnatifid leaves. The ray flowers are white or yellowish. The costomary (P. balsamita) is sometimes used as a source of insecticide, and the feverfew (P. parthenium), mainly varieties with yellow-green leaves, is used as a border ornamental. The genus Pyrethrum is often combined with the genera Leukanthemum and Chrysanthemum. REFERENCEFlora SSSR, vol. 26. Moscow-Leningrad, 1961.T. G. LEONOVA pyrethrum[pī′rē·thrəm] (materials) A toxicant obtained in the form of dried powdered flowers of the plant of the same name; mixed with petroleum distillates, it is used as an insecticide. pyrethrum1. any of several cultivated Eurasian chrysanthemums, such as Chrysanthemum coccineum and C. roseum, with white, pink, red, or purple flowers pyretic Pathol of, relating to, or characterized by fever 3. any insecticide prepared from the dried flowers of any of these plants, esp C. roseum pyrethrum
py·re·thrum (pī-rē'thrŭm), The root of Anacyclus pyrethrum (family Compositae), a shrub native to Morocco; has been used as a sialogogue; its flowers are a source of pyrethrins. [G. pyrethron, feverfew, fr. pyr, fire, from the hot-tasting root] pyrethrum an INSECTICIDE prepared from the dried flowers of the chrysanthemum plant, the active ingredient being called pyrethrin. pyrethrum
Related to pyrethrum: pyrethrinSynonyms for pyrethrumnoun made of dried flower heads of pyrethrum plantsRelated Wordsnoun white-flowered pyrethrum of Balkan area whose pinnate leaves are white and silky-hairy belowSynonyms- Chrysanthemum cinerariifolium
- Dalmatia pyrethrum
- Dalmatian pyrethrum
- Tanacetum cinerariifolium
Related Words- genus Tanacetum
- Tanacetum
- herb
- herbaceous plant
noun spring-flowering garden perennial of Asiatic origin having finely divided aromatic leaves and white to pink-purple flowersSynonyms- Chrysanthemum coccineum
- painted daisy
- Tanacetum coccineum
Related Words- flower
- genus Tanacetum
- Tanacetum
noun used in former classifications for plants later placed in genus Chrysanthemum and now often included in genus TanacetumSynonymsRelated Words- asterid dicot genus
- aster family
- Asteraceae
- Compositae
- family Asteraceae
- family Compositae
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