VEGETABLES. 



241 



all the species of oaks. This term of fructification 

 which I represented at first as insufficient to esta- 

 blish the two principal divisions, is nevertheless of 

 sufficient importance to be admitted as a secondary- 

 character. 



It is well known, that all the species of oaks, are 

 monoecious, and that in the red- oak, {quercus ro^ 

 bur^ Linn.) and in several other species, the male 

 flowers are situated on the young branches, which 

 appear in the spring, and that the female flowers are 

 fixed on these same branches above the male flow- 

 ers : it is known also that both are axilliary^ that 

 immediately after fecundation, the male flowers 

 wither and fall, while the female flowers continue to 

 grow, and in the course of the same year complete 

 their fructification. Such is the ordinary course of 

 nature, but it is not the same with several species of 

 this genus, with which the female flowers which are 

 seen to appear in the spring, stay a whole year with- 

 out growing. It is to be presumed that they are not 

 fecundated in the first year, since it is but after the 

 second spring that they encrease in size, and attain 

 maturity. There is then an interval of eighteen 

 months between the appearance of the flower and 

 maturity of the fruit. These considerations have 

 enabled me to establish two secondary divisions.... 

 One comprehends the species, as I call them, of an- 

 nual fructifications^ that is to say, of which the or- 

 dinary interval of six months is sufficient for the fruit 

 to attain maturity. The other comprehends the 

 species whose fructification is biennial^ that is to 

 say, the fruit of which ripens only every eighteen 



