Definition

1. Noun:
   • A plant genus: A genus name used in older botanical classifications for certain plants, many of which are now classified under the genera Chrysanthemum or Tanacetum.
   • An insecticidal plant: A perennial garden plant of Asiatic origin, with finely divided aromatic leaves and flowers ranging from white to pink-purple. The dried flower heads of this plant are processed to produce a natural insecticide.
   • A specific plant species: A white-flowered pyrethrum species native to the Balkan region, characterized by leaves that are white and silky-hairy underneath. It is also a source of insecticide.

Usage Examples

• Noun:
  • The farmer grows pyrethrum as a natural alternative to synthetic pesticides.
  • Pyrethrum is derived from the dried flowers of certain chrysanthemum plants.
  • This organic spray contains pyrethrum to control aphids.

Advanced Usage

• "Pyrethrum powder": The dried, crushed flower heads of the pyrethrum plant, used directly as an insecticide dust.
  • He applied pyrethrum powder around the base of the plants to deter pests.
• "Pyrethrum extract": The concentrated active compounds (pyrethrins) extracted from pyrethrum flowers, used in liquid insecticide formulations.
  • The pyrethrum extract is mixed with water before spraying.

Variants and Related Words

• Pyrethrin (noun): Any of several related insecticidal compounds that are the active ingredients found in pyrethrum flowers.
  • Pyrethrins are effective against a wide range of insects.
• Pyrethroid (noun): A synthetic chemical compound modeled after the natural pyrethrins found in pyrethrum.
  • Many commercial household insecticides contain synthetic pyrethroids.

Synonyms

• Insecticidal chrysanthemum: A descriptive term for the plant source.
• Dalmatian insect flower: A common name for the species of pyrethrum.

Related Terms and Context

• Natural insecticide: Pyrethrum is a key example of a botanical or natural insecticide.
• Botanical classification: The term illustrates changes in plant taxonomy, as the name Pyrethrum has been reclassified into other genera like .

Noun

1. used in former classifications for plants later placed in genus Chrysanthemum and now often included in genus Tanacetum
2. 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
3. white-flowered pyrethrum of Balkan area whose pinnate leaves are white and silky-hairy below; source of an insecticide; sometimes placed in genus Chrysanthemum
4. made of dried flower heads of pyrethrum plants