CHARLES ] 



THE OAKS 



43 



groups on very short stems in the axils of the springtime leaves. 

 If we examine a branch of the bur oak in the late spring after 

 the fruit has "set", we shall find in the axils of the leaves tiny 

 acorns, successors to the pistillate flowers. If we follow the 

 history of the nuts through the season we shall see them growing 

 rapidly until in mid-October they have fallen from the tree and 

 are urging their roots into the ground during the propitious days 

 of Indian summer. Oaks which thus mature their acorns in one 

 year we may designate as "annual-fruiting". If, now, at the 

 same time, we examine a fruiting branch of the scarlet oak, we 

 shall find a different state of affairs. As in the case of the bur 

 oak, we discover tiny acorns supplanting the pistillate flowers, 

 but in addition to these and much more noticeable are larger 



considerable size, are evidently 



\ 



acorns which, although of 

 "green". Following the career 

 of these larger acorns we find 

 that they mature and drop in 

 autumn, while the smaller 

 acorns, although much larger 

 than in the early summer, are 

 still unripe. Hence it is ap- 

 parent that the scarlet oak 

 requires two years to mature 

 its acorns; or, as we say, it 

 is biennial-fruiting. The min- 

 ute nuts just forming in the 

 late spring are the product of 

 season's flowers, while the 

 larger acorns found on the same branch are 

 yearlings, the product of the flowers of the 

 previous year. During the winter, of course, 

 the scarlet oak retains the unripe crop which 

 is to mature the following autumn. 



In general, we may arrange all oaks, on 

 the basis of their leaves and the period re- 

 quired for their acorns to mature, into two 

 groups : 



( i ) The White Oaks, whose leaves have 

 rounded lobes and are without bristles. These 

 species are annual-fruiting, — that is, their 

 acorns ripen in one year. Examples of this group are the White 

 Oak, Bur Oak, Post Oak, Yellow Chestnut Oak, or Chinquapin, 

 and others ; 



SCARLET OAK TWIG IN 

 THE SPRING SHOWING 

 YEARLY ACORNS AND 

 ONE JUST FORMING 



