46o BOTANY AND PHARMACOGNOSY. 



bark externally yellowish-green or dark brown, wrinkled; frac- 

 ture short, mealy; internally, radiate, yellowish-green, collateral 

 wood bundles forming a concentric zone, bark 4 to 6 mm. thick, 

 cambium zone distinct, center either depressed or more or less 

 prominent; odor slight; taste bitter and aromatic. 



Inner Structure. — See Fig. 198. 



Constituents. — Two yellowish alkaloids, closely resembling 

 berberine and varying from 0.98 to 1.38 per cent, in the bark and 

 1.02 to 2.05 in the wood. To one of these bases the name colum- 

 bamine has been given. Calumba also contains a volatile oil 0.0056 

 per cent., starch about 35 per cent, pectin 17 per cent., resin 5 

 per cent., calumbic acid, calcium oxalate, mucilage, and yields 6 

 per cent, of ash. 



Substitutes. — Various substitutes for calumba have been 

 offered, but these are free from starch, or they may contain tannin, 

 as American columbo, the root of Frasera carolinensis (Fam. 

 Gentianacese), an herb indigenous to the Eastern United States. 

 This root formerly occurred in the market in transverse disks 

 somewhat resembling calumba, but without the radiate structure. 

 It contains a larger amount of a yellow coloring principle and 

 less gentiopicrin than gentian. 



Adulterants. — Calumba has been adulterated with the roots 

 of Tinospora Bakis of tropical Africa and Coscinum fenestratum 

 (both of the Fam. Menispermaceae), the latter growing in India. 

 The disks are woody, the center being prominent and not 

 depressed, and the ash varies from 1 1.9 to 16.6 per cent. 



PAREIRA.— PAREIRA BRA VA.— The root of Chondro- 

 dendron tomentosum (Fam. Menispermaceae), a perennial climber 

 indigenous to Brazil and Peru (p. 274). The commercial article 

 is exported from Rio Janeiro. 



Description. — Nearly cylindrical, more or less tortuous, cut 

 into pieces of various lengths, usually from 10 to 20 cm. long 

 and 10 to 30 mm. in diameter, rootlets few ; externally brownish- 

 black, longitudinally furrowed and transversely ridged and fis- 

 sured, with numerous rootlet-scars and occasional grayish patches 

 of lichens ; fracture fibrous, lustrous when cut ; internally dark 

 brown, with three or more irregular, excentral (Fig. 199), dis- 

 tinctly radiate, concentric zones of secondary fibrovascular bun- 



