COLCHICUM 



85 



spiral tracheae and thin-walled sclerenchymatous fibers. The 

 epidermis consists of tangentially-elongated thick-walled cells having 

 yellowish-brown walls. The addition of sulphuric acid to the sec- 

 tion causes some of the tissues to become yellow, changing to red. 



Powder. (Fig. 32). Light brown or grayish-brown; starch 

 grains numerous, single or 2- to 6-compound, the individual grains 

 varying from spheroidal or ovoid to polygonal, and marked with a 



FIG. 32. Colchicum corm: S, 2- to 4-compound starch grains which make up 

 the greater proportion of the powder; P, parenchyma with numerous starch 

 grains; T, tracheae; E, sieve. 



triangular or star-shaped, central cleft, from 0.003 to 0.030 mm. in 

 diameter; tracheae few and with spiral or scalariform. thickenings; 

 occasional fragments of epidermal cells with thick, reddish-brown 

 walls. 



Constituents. A yellowish, amorphous alkaloid, colchicine, 

 about 0.4 per cent, which has a peculiar odor, particularly on heating 

 slightly, is soluble in hot water and gives with concentrated sulphuric 

 acid a yellowish solution which is colored deep red on heating. If 



