• WordNet 3.6
    • n Pyrethrum used in former classifications for plants later placed in genus Chrysanthemum and now often included in genus Tanacetum
    • n 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
    • n 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
    • n pyrethrum made of dried flower heads of pyrethrum plants
    • ***
Century Dictionary and Cyclopedia
    • n pyrethrum A plant of the genus Pyrethrum; feverfew.
    • n pyrethrum [capitalized] A former genus of composite plants of the tribe Anthemideæ, now included as part of the section Pyrethra in the genus Chrysanthemum, from which it was distinguished by achenes nearly equally from five- to ten-ribbed and crowned with a pappus, characters now known to vary in the same species. The most common species is now called Chrysanthemum Parthenium (for which see feverfew, 1, pellitory, 2, and bertram). Its variety aureum is the golden-feather of the gardens, used for edging.
    • n pyrethrum A powdered preparation of pyrethrum, used as an insectifuge. Also called pyrethrum-powder. See insect-powder and buhach.
    • n pyrethrum In pharmacy, the Anacyclus Pyrethrum, or pellitory-of-Spain.
    • ***
Chambers's Twentieth Century Dictionary
    • n Pyrethrum pir-eth′rum a genus of plants containing the fever-few, or golden-feather, so much used in gardens as a bordering.
    • ***


Chambers's Twentieth Century Dictionary
L.,—Gr.,—pyr, fire.


In literature:

There are very few data at hand concerning the discovery of the insecticide properties of pyrethrum.
"Scientific American Supplement No. 299" by Various
Prof. Riley states that the insects are very readily destroyed by pyrethrum.
"Scientific American Supplement, No. 803, May 23, 1891" by Various
George treated his with pyrethrum powder.
"The Library of Work and Play: Gardening and Farming." by Ellen Eddy Shaw
Mr. Earle will try pyrethrum next season for the tarnished bug.
"Prairie Farmer, Vol. 56: No. 1, January 5, 1884." by Various
Pyrethrum, F. H. Ellison, Minneapolis, second premium, $1.00.
"Trees, Fruits and Flowers of Minnesota, 1916" by Various
Another remedy is pyrethrum.
"Cabbages and Cauliflowers: How to Grow Them" by James John Howard Gregory
The fumes of burning Pyrethrum powder (Persian insect powder), used in the proportion of 2 lbs.
"How to Live" by Irving Fisher and Eugene Fisk
Pyrethrum is used as a spray, mixing one ounce to two gallons of water, to destroy cabbage-worms and many other garden insects.
"Checking the Waste" by Mary Huston Gregory
To clean the room where there are many flies, burn pyrethrum powder (Persian insect powder).
"The Eugenic Marriage, Volume IV. (of IV.)" by Grant Hague
The remedy prescribed is a powder in which pyrethrum is the chief ingredient, sprinkled about the shelves.
"A Book for All Readers" by Ainsworth Rand Spofford
Make it a point to keep the larger-growing kinds, such as Coleus, Pyrethrum and Centaurea, under six inches in height rather than over it.
"Amateur Gardencraft" by Eben E. Rexford
Pyrethrum, anthemis pyrethrum, tobacco, cloves, pepper, cowhage, stizolobium siliqua hirsuta.
"Zoonomia, Vol. II" by Erasmus Darwin
Howard recommends thoroughly rubbing into the fur a quantity of pyrethrum powder.
"Handbook of Medical Entomology" by William Albert Riley
After the plants begin to head, pyrethrum or salt water may be used.
"The Practical Garden-Book" by C. E. Hunn
The pyrethrum may be used dry or in water, at the rate of a tablespoonful to two gallons.
"Farm Gardening with Hints on Cheap Manuring" by Anonymous
In other cases pyrethrum or tobacco powder, wood ashes, etc., have been employed against insects.
"Disease in Plants" by H. Marshall Ward
Insect powder (pyrethrum) will help keep out "croton bugs" and other undesirable household pests, but cleanliness will do far more.
"A Civic Biology" by George William Hunter
If the flies are very numerous, catch them in wire traps, or burn pyrethrum powder in the room.
"Foods and Household Management" by Helen Kinne

In news:

Citronella candles, Japanese coils, pyrethrum sprays—what really protects you from mosquitoes.
Over the past several years, it has been known under a number of names, including Chrysanthemum coccineum and Pyrethrum coccineum.