II VALERIAN ACE^ 227 



female flowers open before tlie male. In some cases, 

 though rarely, complete flowers occur. 



V. pyrenaica. — A native of the South of France and 

 Spain which has become naturalised in plantations. The 

 flowers resemble those of V. officinalis. 



Centranthus 



Tube of the corolla spurred. 1 stamen. 



0. ruber. — The corolla tube is divided into two un- 

 equal parts by a thin membrane : the smaller contains 

 the pistil ; the larger is produced into a spur, but is so 

 narrow that the honey is only accessible to Lepidoptera. 

 The stamen is connate with the corolla, and only 

 becomes free at the base of the lobe ; when the flower 

 opens it projects. When the anther has shed its pollen 

 the pistil elongates and takes its place. According to 

 Knuth, self- fertilisation is therefore excluded, but the 

 stamen gradually curls over so much that the anther 

 might often fertilise a neighbouring flower. It is a 

 Central and South European species often grown in 

 gardens, which has become naturalised, especially in the 

 South of England. 



Valerianella 



Homogamous or protogynous flowers with concealed 

 honey. There are 3 stamens, but the calyx is not 

 pappose. 



We have four species, which are most easily dis- 

 tinguished by the fruits. They consist of three cells, 

 but only one has a seed in it, the other two remain 

 empty. A more or less similar arrangement occurs in 

 other plants, and perhaps serves a useful purpose by 

 reducing the specific gravity of the fruit and thus 

 enabling it to be more easily carried by wind. In some 

 of the foreign species the fruits are provided with hooks. 

 In V. discoidea they are winged. The germinating 

 seedling of F. coronata^ (^''ig- 148) shows an interesting 

 contrivance for fixing the fruit to the soil and thus 



^ Avebury (Lubbock), On Seedlings, 



