192 THE STORY OF PLANT LIFE 



perianth of two whorls. There is a disc which may 

 be annular, or lobed, or reduced to teeth, or is rarely 

 absent. The lower flowers which bloom earlier in the 

 raceme are male, the terminal ones complete. There 

 are four to nine sepals, and, as a rule, five petals, 

 which are distinct. The calyx is deciduous, over- 

 lapping in bud. The petals also overlap in the bud. 

 There are eight stamens (or four to ten) inserted on 

 the disc, which is hypogynous. They are sometimes 

 indefinite. In the male flowers are rudiments of a 

 pistil. The pistil is syncarpous, and consists of two 

 carpels being superior. The ovary is flattened. 

 There are two styles which are slender, united below 

 or distinct, with two stigmas. The style is stigmatic 

 on the inner face. The fruit consists of two, three 

 or four spreading samaras or schizocarps, which 

 break up into mericarps when ripe. The seeds are 

 usually single and without albumen. 



These plants are adapted to insect visits, the 

 flowers being only functionally male or female. The 

 fruits are dispersed by the wind. 



The Maples afford valuable timber-trees. Sugar 

 is yielded by the plant, the sap being sweet. Honey- 

 dew occurs on the leaves, extracted by species of 

 insects, who retail it to ants. 



Field Maple {Acer campestre). 



In the Field Maple, as well as in the Sycamore, 

 where perhaps it is better shown, we have an example 



