[Chap. Ill LEARNING TO NAME PLANTS 25 



a step farther, when white-oak acorns are planted the individual trees 

 that develop are normally all white oaks like the parent trees. These 

 individual white oaks all belong to a single species. Similarly black oaks 

 develop from the acorns of black-oak trees, and only yellow oaks grow 

 from yellow-oak acorns. 



Species that have many fundamental characters in common are 

 grouped together as a genus (plural genera). We do this in common 

 speech when we speak of the "oaks," and we identify the species when 

 we say this is a white oak or a black oak. Botanists long ago began the 

 use of Latin names in order to avoid the confusion arising from the 

 fact that common names applied to the same plant in different localities 

 differ widely, and the impossibility of learning these common names in 

 several hundred languages. The Roman name of the oak is Quercus and 

 the Latin word for white is alba; hence the name chosen for white oak 

 is Quercus alba. All oaks belong to the genus Quercus, and for each 

 species a second name is chosen by the author who first describes the 

 species; by agreement subsequent authors use this same name. This is a 

 great convenience, for students of all countries can use the same lan- 

 guage when referring to the names of plants. These names have come 

 into such general acceptance in all scientific writings that they are often 

 spoken of as "scientific names" in contrast to the "common names" which 

 may vary in every locality and country. 



REFERENCE 



Hitchcock, A. S. Methods of Descriptive Systematic Botany. John Wiley & 



Sons, Inc. 1925. 



(Special references to plant floras adapted to particular regions are too 

 numerous to list. See footnote, p. 24, of this chapter.) 



