CALUMBA 303 



which readily separates, disclosing the yellowish brown bark beneath. 

 The transverse surface is of a dull greyish colour passing to greenish 

 yellow towards the outer margin of the wood and bark. When 

 smoothed with a knife the interior is seen to be much brighter and 

 the section exhibits a thick bark marked with radiating lines (sieve 

 tissue), separated by a dark line (cambium) from the large central 

 portion (wood), in which the vessels are arranged in narrow, rather 

 distant, radially elongated groups. The parenchyma of the wood, 

 like that of the bark, is loaded with starch-grains which under the 

 microscope are seen to be large (20//, to 70yu,) and mostly simple with 



FIG. 152. Calumba root. Transverse section, magnified. (Moeller.) 



eccentric hilum ; near the cork characteristic sclerenchymatous cells 

 with yellow, > irregularly thickened walls and containing prismatic 

 crystals of calcium oxalate are to be found. 



The drug breaks with a short starchy fracture ; it has a slight 

 musty odour and a marked bitter taste. 



The student should observe 



(a) The yellow colour and depressed centre of each slice, 



(b) The thick bark and largely developed parenchymatous tissue, 



(c) The short fracture and abundance of starch. 



Constituents. Calumba root contains three yellow crystalline 

 alkaloids, viz. jateorhizine, columbamine, and palmatine, the latter 

 in small quantity only. 



