THE WOOD SORREL 263 



ment is somewhat different. The petals here are 

 spreading, and do not hold the stamens in position. 

 The latter, however, have spring-like stalks, which 

 are so arranged that, when an insect visits the flowers, 

 they become released, and straighten out in much the 

 same way as in the other species above described. 



The fruit or capsule of the Wintergreens, contain- 

 ing many very small seeds, opens by little slits. The 

 fruits, like the flowers, are pendulous, so the slits arise 

 at the top of the fruit, which is really the base. No 

 valves are, however, formed, such as are found in the 

 fruits of the Bell-flowers (p. 88, Text-fig. IX.). In wet 

 weather, when there is a serious danger of the 

 seeds, still enclosed in the capsule, becoming damp, 

 the slits close. 



The Wood Sorrel. 



Our graceful little Wood Sorrel {Oxalis acetosella, 

 Linn., natural order Oxalidacese, the Oxalis family), is 

 often to be found in the forests of the lower region of 

 the Alpine zone. The creeping, slender root-stock 

 sends up a number of long-stalked, characteristic 

 leaves, each composed of three egg-shaped, delicately 

 green leaflets. These leaves are believed to be those to 

 which the name "Irish Shamrock" was first applied, 

 though the leaves of a species of Clover are now 

 more generally used as that emblem. 



The flowers are borne singly on long stalks, which 

 arise among the leaves. They are large and white or 

 pinkish-white, the petals being extremely delicate. 



