132 



BRITISH FLOWERING PLANTS 



E. cicutarium, var. pimpinellifolium, is protandrous, 

 and fertilised hy insects. The flowers are larger, and 

 the two upper petals shorter, broader, and deeper red 

 than the three lower ones, which, being elongated, form 

 a convenient alighting stage for insects. The upper 

 nectaries are larger and secrete more honey than the 

 lower ones. When the flower opens the pistil is ■ short 

 and undeveloped. First the upper and then the lower 

 anthers open on the side turned away from the pistil. 

 Gradually the filaments turn outwards, and on the 

 second day the pistil has elongated and the stigmas are 

 mature. The petals generally fall on the second day. 

 Finally, the stigmas curl over and often come in contact 

 with the anthers, so that in case of need the flower is 

 self-fertilised. It would appear, however, that the flower 

 diff'ers somewhat according to localities. Besides the 

 complete flowers there are others without 

 anthers, sometimes on the same, some- 

 times on special stocks. These are 

 generally smaller. The flowers of E. 

 moschatum are, according to Ludwig, 

 homogamous or weakly protogynous. E. 

 maritimum, according to the same author,. 

 is sometimes pseudo-cleistogamous. 



The Erodiums have a beak like that 

 of Geranium, but the action is different. 

 The carpels do not open, but contract 

 over the seeds, which thus remain 

 attached to the awn, which is twisted 

 and hairy, as shown in Fig. 77 , which 

 represents a seed of E. glaucophyllum. 

 Nageli has shown that the cell -wall is 

 composed of parallel lamellae of alternate 

 degrees of density and refractive indices. 

 The first series of lamellae are seen in 

 transverse sections of elongated woody 

 cells, as concentric shells, alternately 

 traversing the surface of the cell, and 



Fig. 77. — Awued 

 fruit of Erodium 

 glaucophyllum. 



light and dark, 



are in reality the edges of parallel lamellae of alternate 



