THE ARUM FAMILY 



147 



Fig. 130. — Leaf of 



Colocasia giving 



out a drop of 



water. 



the monsoon, and in swampy soils, there is no clanger of their 

 being dried up. On the contrary, the high percentage of moisture 

 in the ajr ^t that time tends to check the action of transpira- 

 tion. To supplement this vital process^ and to 

 assist in its growth, the plant is enabled to let 

 the ivater pass out in drops from a minute pore 

 at the tip of its leaves (hg. 130), to which free 

 canals, in the substance of the leaves, converge. 

 In this way, room is made for new food-sub- 

 stances to be brought up by the roots. These 

 drops can be noticed especially when the tempera- 

 ture is low, and the air can, therefore, not hold 

 much water-vapour. 



When it rains, the leaves do not become wet; 

 the water runs off in silvery drops, as it would 

 from a duck's back. This is due to a wax-like 

 coat spread over the surface of the leaves. If 

 the water wets the leaves, it will hinder the growth of the plant 

 (see Lotus plant, page 2). 



Cattle are careful to avoid feeding on them; for though they 

 taste sweet at first, they leave a very acrid and disagreeable 

 taste afterwards, which is due to the presence of certain salts in 

 the leaves and stalks. 



2. The Flowers are rarely seen in the cultivated kinds of 

 Colocasia. But they can easily be obtained from the wild variety, 

 as well as from Caladinm bicolor, an allied plant which is grown 

 in gardens for its variegated leaves. In the latter, the flower 

 appears with the first leaves soon after the first rains. What is 

 generally called the flower, is, however, not a single flower but 

 an inflorescence — tJie spadix — consisting of a large, hood-like 

 bract, called the spathe, and a fleshy spike of numerous small, 

 unisexual flowers, so arranged that those at the bottom of the 

 spike are pistillate and those at the top staminate, intercepted 

 by some abortive pistils in the middle. The staminate flowers 

 consist of sessile anthers only each opening by a minute pore at 

 the top, and the pistillate flowers of pistils only all closely 

 packed together on the spadix. 



10* 



