PETALOIDEiE. 



693 



Distribution, §-c. — They abound in tropical countries, but a 

 few also occur in cold and temperate regions. Examples of the 

 Genera: — -Arum, Caladium, Eicliardia. There are about 170 

 species. 



Properties and Uses. — ^The plants of this order are all more 



Fiff. 1066. 



Fig. 1067. 



Fig. 1065. A plant of the Cuckow-pint CAriim maciilatum) in fruit. 6. 

 Underground corm or tuber. I. Leaf. s. The remains of the spatlie. 



c. Fruit. Fig. 1066. The spadix of the same witli the spathe removed ; 



the flowers are all naked and unisexual, the pistillate flowers being 



below, the staminate above, and those in the centre being abortive. 



■ Fig. 1067. Vertical section of the pistil of the same. Fig. 1068. Ver- 

 tical section of the seed. 



or less acrid, and often highly poisonous. This acrid principle 

 is frequently volatile, or decomposed by heat ; hence it may be in 

 such cases more or less destroyed by drj-ing or exposing to heat 

 the parts in which it is found. The best method of getting 

 rid of the acridity is, however, by boiling in water, as the acrid 

 matter is commonly soluble in that fluid. Starch is usually 

 associated with the acrid principle. 



