136 



PLANT ORGANS OR PARTS OF PLANTS. 



which is not common; Madras, which comes in rather 

 large central rhizomes with golden yellow branches; 

 Bengal, which in spite of its dull gray surfaces contains 

 the most color; Cochin, which comes in sections or slices 

 of a rather large rhizome; and Java, in small pieces of 

 little esteem. 



Histology. — The bark, about one-sixth the thickness of 



Fig. 31. — Curcuma. 

 Cross-section cortical portion of turmeric rhizome: k, Cork; p, 

 parenchyma with swollen starch masses; oe, oil cells; g, portion of 

 vessel bundle (Moeller). 



the wood, bounded by an epidermis of thin-walled 

 polygonal or round corky cells, consists of two layers, 

 the outer of irregular pitted parenchyma with somewhat 

 thickened corners without definite arrangement, the 

 inner of regular rectangular cells in radiating rows 

 developed from phellogen. On the surface are numerous 



