6 ^lEDICINAL HEr.BS AND POISONOUS PLANTS 



which is made up of three lobes closely joined together. 



There is still another feature of interest in this flower, 

 namely the prominence of the calyx. It is popularly 

 supposed that the most conspicuous outer parts of a 

 flower must necessarily be the corolla. As a matter of 

 fact, whilst this is the case in the majoxnty of flowers, it 

 is not safe to rely on it; the safest rule to follow is to 

 ascribe to the calyx the outer members, and to the corolla 

 the inner members irrespective of their appearance. In 

 the Snowdrop, for instance, an examination will show 

 that three of the so-called petals are placed outside of 

 the other three; the .inner three must therefore be re- 

 garded as petals, and the outer three as sepals. 



Finall}^ we must mention the differences in tlie flowers 

 brought about by differences in the shape of the recep- 

 taele. This is the name given to that part of the flower- 

 stalk which bears the floral parts. In most flowers the 

 receptacle is just the rounded convex end of the stalk 

 (fig. 7, a). On such a structure the pistil rises from the 

 summit, the other floral parts arising successively im- 

 mediately below it, A flower of this kind is said to be 

 liypofjifnoiis. In other flowers the receptacle takes the 

 form of a ctip (fig. 7,c) or a saucer (fig. 7,6). In both 

 forms the pistil arises from the centre of the cup or 

 saucer, whilst the other floral parts spring from the rims. 

 These flowers are said to be lyerigynous. In another 

 type of perigyny, tlie stamens, corolla, and calyx are 



attached to a disk which encircles the ovary. Tiiis is 

 shown diagrammatically in fig. 7,(?. The disk may be at 



basal 



eptaynotts 



These are 



flowers in which the receptacle has been hollowed out as 

 shown in fig. 7, e, but an advance has been made in that 

 the receptacle has fused with the ovary, so much so that 

 it has become impossible to separate the wall of the ovary 



