234 



BOTANY AND PHARMACOGNOSY. 



less. The inflorescence is a spike-like spadix having greenish- 

 yellow flowers. 



Many of the Aracese possess an acrid juice. The acridity is 

 probably due either to saponin or an acrid volatile principle 

 rather than to raphides of calcium oxalate. Frequently these 

 principles are dissipated or destroyed on cooking and the plants 

 are then used as food, as the water arum (Calla paliisfris). 



Fig. 128. Vanillin, orthorhombic crystals obtained from saturated aqueous solutions. 



which on account of its acrid principles is used as a remedy for 

 snake bites when in the fresh condition, but which on drying loses 

 its acridity and being rich in starch is used as a food (Fig. 128). 

 To this family also belong Jack-in-the-pulpit, or Indian turnip 

 {Ariscema triphylhim), the acrid corm of which is used in medi- 

 cine; SKUNK CABBAGE {Symplocarpus foctidus), the fetid rhizome 

 of which has medicinal properties. A number of plants of the 

 Arum family are rich in starch, as the tubers of Xanthosome edule 

 of Surinam which contain 62 per cent, of starch. 



