Birch, etc — continued. 

 Willow (Salix Caprea), flowers in spring— the earliest of all British Willows. 



Fig". 21. The Fruit of the Oak is the well-known Acorn. 



The woody cup or cupule consists of numerous overlapping scales, and the acorn is simply a Nut 

 In the Birch and Hazel there were two Ovules, only one of which usually forms a perfect Seed; but in the 

 Oak there are six Ovules, and yet only one seed finally survives. 



Fig. 22. Seed with usually two Cotyledons, but sometimes, as in this case, with three. 



Fig. 23. Male Inflorescence, a bushy, soft mass of golden-yellow Stamens. 



Fig". 24. Detach a single Flower with its accompanying Bract. 



Two Stamens constitute the flower, with a small Disc at the base. 



Fig. 25. Female Inflorescence, elongated and of a silver-grey colour. 



Fig. 26. Detach a single Flower from the central axis. 



Two united Carpels constitute the flower. 



Fig. 27. The capsular Fruit splits along the midrib of each carpel, and the two valves curl over at the top, exposing the hairy 

 Seeds. 



Fig. 28. Each Seed is enveloped by a pencil of silky hairs springing from the base. 



CLASSIFICATION. 



Class. — Dicotyledon. 



Leaves, net-veined. 



Embryo with two cotyledons. 



Orders. — Betulacese (Birch and Alder). 



Male and Female flowers on same tree. 

 Female flowers without perianth. 



Ovary, two-chambered, with one Ovule in each chamber. 

 Fruit, a flattened nut, usually winged and without investment 

 Corylaces (Hazel). 



Male and Female flowers on same tree. 

 Female flowers with rudimentary perianth. 

 Ovary, two-chambered, with one Ovule in each. 

 Fruit, a nut, with leafy investment 



Cupuliferae (Oak). 



Male and Female flowers on same tree. 

 Male and Female flowers with perianth. 

 Ovary, three-chambered, with two Ovules in each. 

 Fruit, a nut, with cupule. 



Salicacese (Willow). 



Male and Female flowers on different trees. 



Disc, representing Perianth. 



Ovary, one-chambered, with numerous Ovules. 



Fruit, capsular, splitting into two valves. 

 Seeds, numerous, with silky hairs. 



