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SCIENTIFIC AND APPLIED PHARMACOGNOSY 



about 2.5 to 4 cm. in thickness; externally oyster-white or yellowish- 

 white, and marked by numerous circular root-scars; hard and heavy; 

 fracture irregular, the broken surface exhibiting a distinct endodermis 

 and numerous circular vascular bundles. It has a violet-scented odor 

 and a slightly aromatic, somewhat bitter and acrid taste. 



Inner Structure. Consisting mostly of starch-bearing paren- 

 chyma, in the intercellular spaces between which occur large prisms 

 of calcium oxalate, varying from 0.100 to 0.500 mm. in length and 

 from 0.015 to 0.025 mm. in diameter. The walls of the endodermal 

 cells are of a collenchymatous nature and contain starch. The 

 fibrovascular bundles are of the. leptocentric type and the tracheae 

 show mostly annular or spiral thickenings, although scalariform or 

 reticulate forms may occur. 



K 



'a 



pr- 



FIG. 47. Orris root: pr, parenchyma containing starch grains; a, starch grains 

 with characteristic cleft; pr', parenchyma with narrow oblique pores; sp, 

 fragments of tracheae; K, prisms of calcium oxalate. After Vogl. 



Powder. (Fig. 47.) Starch grains, 0.005 to 0.030 mm. in diam- 

 eter with a characteristic cleft like a pair of open shears. Calcium 

 oxalate in solitary prismatic crystals with pyramidal ends and attain- 

 ing a length of 0.500 mm. Trachese with markings as indicated 

 above. There are neither cork cells nor sclerenchymatous fibers 

 present. 



Constituents. From 0.1 to 0.2 per cent of a yellowish-white 

 volatile oil which is almost solid at ordinary temperatures, whereby 

 it is known commercially as orris butter. It consists chiefly of myris- 

 tic acid and owes its odor to the ketone, irone. It also contains a 

 small amount of a crystalline glucoside, iridin, which is soluble in 

 hot alcohol, sparingly soluble in water and insoluble in ether, chloro- 



