ROOTS AND RHIZOMES. 
133 
cloudy mixture with water, and gives with alcoholic 
lead acetate test-solution a reddish-brown precipitate 
and a liglit-brown filtrate. 
PYKETHKUM (Pellitory). 
The root of Anacyclus Pyrethrum (Fam. Compositse), 
a perennial herb indigenous to Northern Africa and 
Southern Europe, the commercial article coming from 
Algeria. The root is collected in autumn and dried. 
Description. — Nearly cylindrical, slightly tapering 
or broken into irregular pieces, 2'5 to 10 cm. long, 3 to 
20 mm. in diameter; externally dark brown, wrinkled 
and somewhat furrowed longitudinally, with few rootlets 
or rootlet scars; crown somewhat annulate from scars of 
bud-scales, and sometimes tufted with coarse fibers of 
fibro vascular tissue or with long, soft-woolly, nearly 
straight one-celled lmirs; fracture short and horny 
when dry, tough when damp; internally, bark dark 
brown, with two circular rows of secretion reservoirs, 
0 5 to 1 mm. thick, and closely adhering to the light- 
yellow radiate porous wood, in the medullary rays of 
which secretion reservoirs are also found ; odor distinct, 
penetrating; taste pungent, acrid. 
Constituents. — An alkaloid pyrethrine, which oc- 
curs in colorless, acicular crystals and has an intense 
pungent taste ; fixed oil, volatile oil, resin, and 50 per 
cent, of inulin. 
Allied Plants.— German pellitory, the root of Ana- 
cyclus oflicinarum, is smaller; the bark contains but one 
row of secretion reservoirs, which are wanting in the 
medullary rays; the roots also contain tannin. 
SENEGA (Senega Root). 
The dried root of Polygala Senega (Fain. Polygalaceae), 
a perennial herb indigenous to the Southern United 
States. There are two representative commercial varie- 
