554 ARUM TRIBE. 



here we have the most necessary organs of fructification, reduced 

 almost to the lowest condition in which they can exist. In a 

 few of the tribe, however, a perianth is present, consisting of 

 four or six pieces. The fruit of the common Arum ripens in 

 the form of a spike of orange-coloured roundish berries, each 

 containing but a single seed. Other species of the order differ 

 from this in the spadix being entirely covered with flowers, in 

 the absence of abortive ovaries, and in such other details. The 

 peculiar character of the order is derived from the close arrange- 

 ment of the flowers upon the central column or spadix, and the 

 inclosure of the whole within a large spathe. 



731. The Araceas are very abundant in tropical countries, 

 but become fewer in number in proportion to the distance from 

 the equator. In cold or temperate climates they are usually 

 herbaceous ; but in tropical countries they attain a considerable 

 size, frequently growing over large trees, to which they cling 

 by means of aerial roots. They are for the most part acrid, and 

 some species are extremely poisonous : one of the most remark- 

 able effects which any of them produce, is occasioned by the 

 Dumb Cane (as it is called), a native of the West Indies and 

 South America, which has the power, when chewed or even 

 bitten, of causing the tongue to swell to such a degree that it 

 cannot be moved in the mouth ; at the same time occasioning 

 very severe pain, from which recovery does not take place for 

 some days. The stems or rootstocks, however, possess this 

 acridity in a diminished degree ; and as it is further dissipated by 

 heat, they become valuable articles of food. Those of the Spotted 

 Aruin are used for this purpose in the Isle of Portland ; and 

 the starchy produce obtained from them is even sent to London, 

 under the name of Portland Sago. In the West Indies, the 

 tubers of another species are commonly eaten under the name of 

 Eddoe. One of the most innocent species is that known in 

 Britain under the name of Scented Flag-rush ( Acorus calamus), 

 which is aquatic in its habits, as its common name implies. 

 The rhizoma of this plant contains a considerable quantity of an 

 aromatic essential oil, which imparts its fragrance to the mealy 



