OAK 99 



The tree. is perhaps best known by its stout and lofty bole or base 

 of the trunk. The stem is erect, branched, the branches ascending or 

 spreading, never drooping. 



Reaching a height of 150 ft., and having an enormous girth, up 

 to 70 ft. in circumference, the Oak is one of the largest British trees. 

 The Newland Oak, for instance, has a girth of 60 ft., the Cowthorpe 

 Oak, Yorkshire, being 70 ft. The thick trunk, which is usually short, 

 gives rise to several thick long arms, the lower often horizontal, the 

 upper ascending and spreading, forming an elbow or angle, and thus 

 giving it a twisted appearance. This arrangement makes the crown 

 a semicircular one, and in this variety in the summer appearance the 

 foliage is in dense masses, broken by the elbows of the branches, and 

 at no distance from the ground. In the winter stage the irregular 

 branching is well seen. 



The resting buds have numerous pairs of scales or stipules of un- 

 developed leaves. The lateral buds are in clusters at the tip of the 

 twigs. The lower buds are inactive for long periods. This causes 

 the zigzag arrangement of branches. The leaves are lobed, spirally 

 arranged, 4 in the tufts at the ends of branches. The leaves are 

 stalked and have temporary stipules. The stalk is short, the blade 

 is hairless, not tapered at the base. The leaves fall in November. 



The Oak is a moncecious plant, and both male and female catkins are 

 borne on the same shoot. The male on the dwarf shoots are pendent, 

 and both male and female occur on terminal parts of the previous year's 

 twigs. There is one stalkless female flower in the axils of the bract 

 scales. The male catkin has many catkin scales. The male flowers 

 have 5-7 united sepals, 5-12 stamens. The female inflorescence has 

 fewer flowers (1-5), and has a distinct stalk with lateral flowers. The 

 fruit, an acorn, is developed from a i -seeded ovary, 5 of the ovules not 

 developing. The cupule or cup has close overlapping scales. The 

 acorns are distant. The three carpels are united with a three-chambered 

 ovary and 2 ovules in each chamber. Five of the 6 ovules do not 

 mature. 



The tree may be 60 ft. high. It flowers in April and May. It 

 is a deciduous tree, propagated by seed. Like other Cupuliferse the 

 flower is pollinated by the wind. Each spike contains one female 

 flower, which forms the acorn cup at the base, or a cluster of flowers. 

 The male flowers hang in drooping catkins, with 10 projecting stamens. 



The fruit or acorn when ripe drops, owing to its great weight, to 

 the ground, and is later released from the cupule, or it may be carried 

 by birds or animals to a distance as food, whilst being semi-detached 



