138 GENERAL BOTANY 



colour). Many other instances of the same sort of simi- 

 larity between different species will occur to the 

 reader. 



We thus see that just as plants can be grouped 

 into species, species can also be grouped. A group 

 of species possessing in common certain character- 

 istics of flower and fruit, though differing in habit 

 perhaps and in their leaves (characters which we have 

 already learnt are of minor importance) is called a 

 genus. Thus the Banyan, the Peepul and the country 

 Fig, belong to a genus known scientifically as FICUS. 

 It is a very large genus, comprising a large number of 

 species, most of them trees, and all with a sticky 

 milk-white juice, large hood-like stipules, and minute 

 imperfect flowers aggregated inside a hollow receptacle, 

 but differing among themselves in their general habit 

 (the Banyan for instance has roots hanging down 

 from the branches, the Peepul and Fig have not), in 

 the appearance of the leaves and fruit and other 

 characters of lesser importance. 



In the same way the Bullock's heart, Custard-apple 

 and Sour-sop are three species belonging to another 

 genus named ANONA, because similar to each other 

 in the chief characters of flowers, fruits and seeds, but 

 differing in their leaves, and in the outward appearance 

 of the fruit. 



It has been found convenient therefore to give 

 to every species, two names, one of its genus the 

 other its own special name, and it is usually necessary 

 and sufficient in describing a plant to give these two 

 names, the genus always first, the species second. 

 But to add clearness and preciseness to the name, and 



