54 



Under the microscope are found thick walled, lignified bast fibres, 

 which are not usually found in aggregates. Single starch grains 



Q ®0 



Fig. 49. Sassafras. 



Figure 49 

 (1) Lignified bast fibres; (2) Starch grains. 



and aggregates of two or three are often found, the grains ranging 

 in size from 7 — 20/x. Irregular masses of tannin are found in the 

 parenchyma tissue, and usually there are numerous oil globules 

 present. Fig. 49 shows the elements of sassafras which are an 

 aid to its diagnosis when found in condimentals. 



SENNA. 



{Cassia spp.) 



This drug is sometimes found in condimentals. In bulk the 

 powder has a greenish color and a characteristic bitter taste. 



Fig. 50. Senna. 



Figure 50 

 Non secretion hairs from leaf. 



Under the microscope are usually found numerous non-secretion 

 hairs from the under side of the leaf. These are quite character- 

 istic and vary in length from 0.1 — 0.2 m.m. ; are pointed, broadly 

 awl shaped with distinct walls, and are unicellular. Fragments 

 of the powder become reddish in color upon the addition of alkali. 

 Calcium oxalate crystals arc found which are both rosette sha]3ed 

 and in monoclinic [msnis from 10 — 35/i in length. (Fig. 50.) 



