DANDELION G87 



tracheae reticulate, narrow; sclerenchymatous fibers few; resin canals 

 containing yellowish-brown amorphous masses of a volatile oil and 

 resin. 



Constituents. An alkaloid pyrethrine, which occurs in colorless, 

 acicular crystals, has an intense pungent taste, and which is decom- 

 posed by alkalies into piperidine (a pungent principle occurring in 

 black pepper) and pyrethric acid, a principle resembling piperic acid. 

 Pyrethrum also contains a brown acrid resin, two other acrid resins, 

 a volatile oil and about 50 per cent of inulin. 



Allied Plants. German pellitory, the root of Anacyclus officin- 

 arum, is smaller; the bark contains but one row of secretion reservoirs, 

 which are wanting in the medullary rays; and the roots contain 

 tannin in addition to the constituents found in Pyrethrum. 



TARAXACUM. Dandelion. The root of Taraxacum officinale 

 (Fam. Compositse), a perennial herb indigenous to Europe and Asia, 

 but now naturalized in all civilized parts of the world. The root 

 should be collected in spring or in autumn either directly before or 

 after the vegetative activity of the plant. It is used in either the 

 fresh or dried condition, the principal supply of the dried root coming 

 from Europe. The pith of the rhizome portion is liable to be attacked 

 by insects. The product should be stored in tightly closed con- 

 tainers, to which a few drops of chloroform or a carbon tetrachloride 

 should be added, from time to time, to prevent the development of 

 insects. 



Description. Somewhat cylindrical, tapering, more or less 

 flattened, slightly branched or broken into irregular pieces 6 to 15 

 cm. in length, 5 to 15 mm. in diameter; externally light brown, 

 wrinkled, with numerous rootlet-scars; crown simple or branched 

 slightly annulate from numerous leaf -bases; fracture short, horny 

 when dry, tough when damp; internally, bark light brown, 2 to 6 

 mm. in thickness, made up of concentric layers of laticiferous vessels 

 and sieve alternating with white parenchyma, wood lemon-yellow, 1 to 

 4 mm. in thickness, porous and non-radiate; odor slight; taste bitter. 



INNER STRUCTURE. See Fig. 303. 



Powder. Light brown; parenchyma containing irregular crys- 

 talloidal masses of inulin; laticiferous vessels yellowish-brown; 

 trachese reticulate; intermediate fibers non-lignified, with irregular 

 simple and oblique pores. 



Adulterant. The roots of one or more species of Lactuca have 

 been substituted. The wood is radiate, the trachese being one cell 

 wide alternating with medullary rays two or three cells in width. 

 (U. S. Dept. Agric.) 



