260 



THE STUDY OF TREES. 



the spring before the leaves. Wind pollinated. Fruit 

 single- seeded, with membranous expansion all round 

 (samara). Leaves alternate, ovate, unequal lobed, pointed, 

 serrated, veins prominent. Bark rough, longitudinally 

 fissured. 



Goat Willow (Salix caprea). Male and female catkins 

 upon separate plants. Male catkins golden yellow; each 

 flower consists of a bract, two stamens and a nectary ; 



Fig. 136. The Elm, with clusters 

 of fruits. 



Fig. 137. The Willow, with male (lower) 

 and female (upper) catkins. 



female catkins greenish, flowers also with a nectary. 

 Flowers ripe before the leaves. Pollinated by humble- 

 bees and moths chiefly in April. Fruit a capsule. Buds 

 silky. Leaves ovoid, elliptical or lanceolate. 



Black Poplar (Populus nigra). Male and female catkins 

 on separate plants. Stamens numerous (12-20), stigmas 

 branching. Flowers ripe before leaves appear. Wind- 

 pollinated. Fruit a capsule. Leaves on long stalks flat- 

 tened, broad, tapering, sometimes almost triangular, smooth 

 texture tough, Bark rough, grey. 



