18 THE STORY OF PLANT LIFE 
Certain types of woodland are characterised by the 
dominance of either the pedunculate or sessile types 
of Oak. The former grows on clays and loams, the 
latter on sandstones. 
There are a few old Oaks which date from about 
the time of the Conquest, but they are few and far 
between. In addition to forming forests and woods, 
the Oak is commonly planted in hedgerows along the 
roadside and in fields, parks and gardens. 
The trunk is thick and massive but it reaches a 
height of 60 ft., or even more when well-grown. The 
bark is furrowed, the furrows not so wide as in the 
Elm. The trunk is erect, with wide, outspreading, 
massive branches, others ascending in a radiate 
manner. The leaves are yellowish green in the 
pedunculate form, dark green in the other, on short 
petioles in the one or sessile. They are thick, coria- 
ceous, shiny, sinuate, dentate, the lobes deep. 
The flowers are apetalous, green, the male flowers 
in drooping catkins with a bract below, and the 
female in a clustered spike, the bracts overlapping 
and forming an involucre. The fruit (an acorn) is 
one-seeded, oblong, pedunculate or sessile, enclosed 
in a cupule below of imbricating scales. The acorns 
are distant. 
The flowers are in bloom in April and May. 
The flowers, as in most other trees, are pollinated 
by aid of the wind. The acorn when ripe drops from 
the tree from sheer weight. It is also dispersed by 
squirrels and other rodents, and by birds, especially 
