PARTS OF ROOTS AND STEMS. 
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Constituents. — A bitter, somewhat resinous princi- 
ple, viburnin ; valerianic (viburnic acid) and other 
organic acids; resin; tannin; calcium oxalate; ash 
about 10 per cent. 
GOSSYPII RADIOS CORTEX (Cotton Root Bark). 
The dried bark of the root of Gossypium herbaceum, 
and of other species of Gossypium (Fam. Malvaceie), 
biennial or triennial shrubs indigenous to Subtropical 
Asia and Africa, but now cultivated in all tropical and 
subtropical countries. 
Description. — In flexible, transversely curved or 
slightly quilled pieces, 6 to 30 cm. long, 5 to 15 mm. 
in diameter, bark 0‘2 to 1 mm. thick; outer surface 
light brown, longitudinally wrinkled, with small lenti- 
cels, periderm frequently exfoliated; inner surface 
light brown, longitudinally striate ; fracture tough, 
fibrous, surface light brown, tangentially striate, readily 
separable into fibrous layers; odor faint; taste slightly 
astringent and acrid. 
Constituents. — A yellowish resin ; a yellow coloring 
principle becoming reddish and resinous with age ; 
fixed oil ; tannin ; starch and calcium oxalate. 
RUBUS (Blackberry Root Bark). 
The bark of the root of Rubus nigrobaccus Bailey, 
and of other species of Rubus (Fam. Rosacese), peren- 
nial shrubs indigenous to the Eastern and Central 
United States. The bark should be collected in spring 
or autumn and dried. 
Description. — In flexible, transversely curved or 
slightly quilled pieces 4 to 20 cm. long, 3 to 5 mm. 
in diameter, bark 0'2 to 2 mm. thick ; outer surface 
light brown, longitudinally wrinkled, with few root- 
scars, periderm frequently exfoliated ; inner surface 
