CHARACE^E 409 



CHARACE^E 



Various members of this family are found growing in 

 stagnant, or slowly flowing fresh water : they are green, 

 but owing to superficial lime incrustations, they may 

 appear white and chalky, especially when dry : they are 

 brittle in texture, and are commonly called Stone- Worts. 

 They grow rooted in mud, and put up into the water a 

 branched shoot, which may be a foot or more in length : 

 this bears at intervals whorls of lateral appendages the 

 " leaves." In summer and autumn these bear the sexual 

 organs in large numbers, the antheridia being specially 

 prominent owing to their bright red colour. The odour 

 of these plants is characteristic, being like that of 

 onions. 



There are two chief genera of the family, viz., Chara 

 and Nitella (besides other subgenera) : the most obvious 

 difference between these is that Chara is more robust, 

 the stem and leaves having a peripheral cortex, while 

 Nitella has none. A large number of species are dis- 

 tinguished, and as it might be difficult for beginners to 

 recognize any one definite species with certainty from 

 others, the description given below will be confined to 

 the more essential characters of the genus Chara, while 

 Nitella will be dealt with incidentally in small 

 type. 



