160 CLASSIFICATION OF TLANTS. 



duced by the application of the pollen of one species to the 

 stigma of a nearly allied species. Nature perhaps often exhib- 

 its the products of this operation to the perplexity of the bot- 

 anist. The seeds of hybrids rarely germinate, although they 

 may appear perfect. 



307. A genus is a group of nearly related species. Many of 

 the genera are made up of species so nearly and obviously re- 

 lated, that the most common observer would at once adopt the 

 same grouping. The oaks, pines, lilies, &c., are natural genera. 

 Sometimes some of the species are more nearly related to each 

 other than to the other members of the genus. These are 

 grouped as sub-genera. 



308. Genera are founded entirely on the character of the 

 floral organs : the species, on the whole plant. To be of the 

 same genus, the plants must have a general agreement as to 

 the floral organs : to be of the same species, they must agree 

 throughout, from root to fruit. 



In naming a plant we give it two names : the name of the 

 genus and the name of the species. Thus the common maple 

 is Acer ruhrum. Acer is the genus including all maples, ru- 

 hrum is this particular kind of maple : the former is called th» 

 generic, the latter the siyecific or trivial name. 



309. Generic names are variously derived. Sometimes in 

 honor of some man ; as Kalmia, in honor of a Swedish botanist, 

 Kalm. At other times, from the general locality of the species ; 

 as Ranunculus, from growing in marshy places, which frogs in- 

 habit. Sometimes from some quality or structure of the plants ; 

 as Sanguinaria, blood-root, &c. The generic name is always 

 considered to be a Latin noun, in the nominative case singular, 

 and takes its gender according to the laws of that language. 

 The specific name is an adjective generally, and must agree in 

 gender with the generic name, with the termination of Latin 

 adjectives. If the specific name is derived from a proper name, 

 or from an old genus, it must retain its capital initial letter. If 

 the name is given in honor of the discoverer of the plant, or 

 its describer, it must be put as a noun in the genitive case : thus 

 Aster Curtisii shows that Mr. Curtis presented this plant to the 

 world as a discoverer, or that he pointed out its peculiar char- 

 acters, that made it a new species. If simply in honor of an 

 individual, it is formed into a Latin adjective, and must agree 

 in gender with the genus ; thus Aster Lindleyanus is an Aster 

 named in honor of Dr. Lindley, with which perhaps he had no 

 acquaintance. 



310. Orders are formed by grouping together several genera 

 agreeing in some general characters. Thus Com^yositce in- 



