428 



SCIENTIFIC AND APPLIED PHARMACOGNOSY 



and rootlets are removed. The drug frequently is seen in commerce 

 in small pieces about 5 mm. in diameter having a uniform grayish- 

 white color, otherwise resembling the entire root. 



Description. Nearly entire, cylindrical, tapering, 10 to 20 cm. 

 in length, 5 to 20 mm. in diameter; externally very light brown, 

 obscurely 4- to 6-angled, deeply furrowed longitudinally, covered 

 with detachable bast fibers, with few circular root-scars; fracture 

 of bark tough, fibrous, of wood short and granular; internally light 

 brown, finely radiate, bark 0.5 to 2 mm. in thickness, and easily 

 separable from the wood, cambium zone marked by a distinct brown 

 line, wood porous; odor faint, aromatic; taste sweetish, mucilaginous. 



INNER STRUCTURE. See Fig. 187. 



B 



FIG. 187. Althaea Radix: A, transverse section of portion of the bark; m, 

 medullary rays; sch, mucilage cells; p, parenchyma; s, leptome plates; sc, 

 groups of bast fibers; o, rosette aggregates of calcium oxalate. B, trans- 

 verse section through a portion of the wood; G, trachaea, having porous 

 walls; T, tracheid-like wood fibers; sc, wood fibers; p, wood parenchyma; 

 m, medullary rays; sch, mucilage cells; O, rosette aggregates of calcium 

 oxalate. After Meyer. 



Powder. Very light brown; groups of sclerenchymatous fibers, 

 the latter having thick more or less lignified walls; starch grains 

 numerous, from 0.005 to 0.020 mm. in diameter, ellipsoidal, usually 

 having a long central cleft; tracheae with scalariform thickenings or 

 with bordered pores; calcium oxalate crystals few, in rosette aggre- 

 gates, 0.020 mm. to 0.030 mm. in diameter. 



Constituents. Mucilage 25 to 35 per cent; asparagin (amido- 

 succinamide) 1 to 2 per cent, which occurs in hard crystals having 

 an acid reaction, insoluble in alcohol but soluble in 50 parts of cold 

 water; starch about 35 per cent; pectin about 10 per cent; sugar 



