Chrysan'themum (Pyrethrum) ro'seum and C. Car'neum, Persian Pellitory -- Persian (Caucasian) Insect Powder; W. Asia, Persia. Perennial plants, resembling chamomile; flower-heads 4 Cm. (1 3/5') broad; ray-florets rose-color with anthers included (roseum), or purple with anthers projecting (carneum); powder grayish-yellow, brownish (best), bright yellow (weakest), tea odor, bitter -- used only for killing insects, the toxicity being due to pyrethron (pyrethrotoxic acid -- cardiac depressant like veratrine), a neutral, amber-yellow syrupy ester (pyretol) soluble in alcohol, ether, splitting into pyrethrol, C21H34O), and several acids, pyrethresin.

C. Cinerariaefo'lium, Dalmatian Insect Powder; Dalmatia. These flowers are most valuable when collected immediately after expansion, and yield a more or less inferior insect powder -- greenish-yellow. Plant cultivated in Algeria, Japan, Montenegro, and largely in California, where flowers are dried carefully (to preserve color and volatile oil) -- furnishing a superior powder, called "buhach." Should not contain more than 5 p.c. flower-stems or 2 p.c. acid-insoluble ash. Tests: 1. Put 4 gr. (.25 Gm.) of the powder upon a fly in a vial -- it should be stupefied in 1 minute and dead in 2 or 3 minutes. 2. With microscope can recognize scarcity of pollen and abundance of collenchymatous tissue when much stem and few flowers are used. Powder often adulterated with turmeric (chloroform test), chrome alum (ash not more than 6 p.c.), and other compositous plant flowers, as Chrysanthemum Leucan'themum (Leucanthemum vulga're), white-weed, oxeye or field daisy, and C. Seg'etum. Neither of these is an insecticide but will produce dermatitis in some persons.