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SCIENTIFIC AND APPLIED PHARMACOGNOSY 



which occurs as a brown-black powder and yields on hydrolysis 

 senna-emodin (tri-oxymethylanthraquinone) and senna-chrysophanic 

 acid (di-oxymethylanthraquinone). (See Rhubarb.) Anthragluco- 

 sennin when acted upon by alkalies produces an amorphous, black 



FIG. 143. Cassia angustifolia (India senna): A, transverse section through the 

 middle vein showing upper epidermis (E), palisade cells (P), rosette aggre- 

 gate of calcium oxalate (Od), monoclinic prisms of calcium oxalate, (o), 

 tracheae (G), sieve (Sg), sclerenchymatous fibers (F), lower epidermis with 

 rather thick-walled cells (E). B, transverse section through portion of 

 leaf between the veins showing the absence of monoclinic prisms of calcium 

 oxalate, the presence of palisade cells and stomata on both the lower and 

 upper epidermis, and a hair (//) on the lower surface. C, lower epidermis 

 on surface view. D, upper epidermis showing stomata and a single hair. 

 E, diagram of section through the middle vein, the letters corresponding to 

 those in A. After Meyer. 



powder, senna-nigrin, which also yields on hydrolysis emodin and 

 chrysophanic acid. Senna also contains a yellowish, amorphous 

 glucoside, glucosennin; a reddish-brown, amorphous substance, 



