HYDRASTIS 



211 



Powder. (Fig. 91.) Bright yellow to brownish-yellow; starch 

 grains numerous, from 0.002 to 0.015 mm. in diameter, being mostly 

 single, nearly spheroidal, and either free or in the parenchyma cells; 

 fragments with the tissues of the fibrovascular bundles mostly 

 associated with starch-bearing parenchyma; tracheae, with simple 

 and bordered pores and occasionally spiral thickenings, and asso- 

 ciated with short sclerenchymatous fibers possessing thin walls 

 with simple pores; occasional fragments of tabular cork cells with 

 reddish-brown walls. 



FIG. 91. Hydrastis: P, parenchyma; S, parenchyma containing starch; T, 

 tracheae with annular and reticulate thickenings of the walls; F, tracheids 

 with simple pores; C, cambium; K, cork; B, parenchyma cells showing the 

 separation of acicular crystals of one of the alkaloids on the addition of 

 concentrated sulphuric acid; H, prisms of one of the alkaloids which sepa- 

 rate on the addition of concentrated sulphuric acid to a powder previously 

 moistened with water. 



Constituents. Two alkaloids one, hydrastine, occurring to 

 the extent of 2 to 3 per cent, and forming colorless, tasteless 4-sided 

 prisms, although the salts are pale yellow and bitter; the other, 

 berberine, occurring to the extent of 3 to 4 per cent in the form of 

 yellow rods (Fig. 92), which are bitter and readily form compounds 



