422 COMPOSITE 



555. PYRETHRUM. PYRETHRUM 

 PELLITORY. ROMAN PELLITORY 



The root of Anacy'clus pyre'thrum (Linne") De Candolle. Preserve in tightly 

 closed containers, adding a few drops of chloroform or carbon tetrachloride, to 

 prevent attack by insects. 



BOTANICAL CHARACTERISTICS. Root long, fusiform. Stems numerous, branched, 

 pubescent. Radical leaves pinnatifid, stem-leaves sessile. Florets of the ray 

 pistillate, white above and purplish beneath; of the disk, yellow, tubular, 

 5-toothed. Akene flat, winged; pappus short. 



SOURCE. Mediterranean Basin, coming solely from Algeria, thence to 

 Mediterranean points. 



PIG. 250. Pyrethrum Cross-section of root, (n diam.) A, Cork. B, Ring of stone-cells. C, Par- 

 enchyma of primary cortex. D, Cambium. E, Medullary ray. F, Xylem. (Photomicrograph.) 



DESCRIPTION OF DRUG. A hard, compact, somewhat fusiform root, 

 about the size of the little finger, with sometimes leaf-remnants at the 

 top, and beset with few or no hair-like rootlets; externally brownish, 

 deeply fissured longitudinally. It breaks with a short fracture, 

 showing a rather thick bark adhering closely to the pale brown wood, 

 from which it is separated by a narrow cambium line. This woody 

 column is traversed by broad, distinct medullary rays, and contains, 

 as does also the bark, large scattered resin ducts. Odor very slight; 

 taste slight at first, but afterward persistently acrid, leaving a sin- 

 gular tingling sensation in the mouth and throat, and exciting a re- 

 markable flow of saliva. 



555 a. Pyrethrum Germanicum, from Anacydus officinar.um Hayne, is of 

 a grayish color, about half as thick as above, tapering to filiform at 

 the lower end; has long been cultivated near Magdeburg and in 

 Saxony. It resembles the above in foliage and flowers. 



