308 COMMON TREES AND SHRUBS 



sometimes there are only four), seven stamens, and a superior 

 pistil of three united carpels. The ovary is three-celled, 

 with two ovules in each, and above is a single long style. 

 At the bases of the young petals are yellow spots which 

 later turn red. The anthers and pollen are also red. 



The flowers are visited by bees and are well adapted to 

 the size and habits of the humble-bee. The upper flowers 

 with an abortive ovary, open first (Fig. 203, 1). Later, 

 the perfect flowers open, the style projecting horizontally, 

 and the stigma is ripe before the stamens, which, at this 

 stage, hang downwards out of the way (2). Thus pollen 

 may be carried by bees from the male flowers to the 

 stigmas of the perfect flowers. Finally, the stamens turn 

 upwards, parallel to the style, and shed their pollen, and 

 so may effect self-pollination (3). The bee presses its 

 legs between the petals, and pushes its proboscis into the 

 flower to obtain honey from the disk on the outside of the 

 stamens. In doing so, the hinder part of its body touches 

 the stigma and also the ripe anthers, and at the same time 

 it carries away pollen on the bases of its middle and hind 

 legs. The fruit is formed from the ovary and becomes a 

 large and spiny capsule. When ripe it splits into three 

 valves, each containing two large brown seeds. 



Common Ash 



The Common Ash (Fraxinus excelsior) (Fig. 204) is a 

 native tree, widely distributed in Britain in very different 

 habitats. It is especially characteristic of the woods of 

 the rocky and scree-covered limestone hills in the north 

 and west of England, in which it is usually the dominant 

 tree. In non-calcareous areas it is common in the wet 

 soils along stream-sides and is frequent in the wet carr 

 woods of lowland and fen districts." It is sometimes cop- 

 piced. The tree attains a height of eighty to a hundred 



