CYCLIC FLOWERS 69 



whorl of the flower are aUke, the flower is regular {e.g. Wall- 

 flower, Poppy, Geranium, Hyacinth). 



(iii.) Atrophy and Suppression. — By the' word atrophy we 

 mean the dwarfed development of a structure : atrophy, there- 

 fore, is a special example of unequal growth. Staminodes are 

 examples of atrophy; they are stamens which have not pro- 

 duced their anthers. Comparing various flowers of the 

 Umbelliferae or Compositae : in some we find the calyx repre- 

 sented by five minute teeth (fig. 183 ex), it has undergone 

 atrophy ; in still others no calyx is represented, it is entirely 

 missing, and we then speak of the suppression of the calyx. 

 In the Foxglove and the Dead Nettle, though there are five 

 sepals and five petals represented in each flower, only four 

 stamens occur. In each case one stamen which should 

 alternate with two of the petals is missing. In the Primrose 

 and the Iris a whole whorl of stamens is suppressed : in the 

 former flower, the outer whorl is absent (see p. 149), so that 

 the five stamens are opposite to the five petals ; in the latter 

 flower the three inner stamens are wanting (see p. 173), so 

 that the three carpels are opposite to the three stamens. 



(iv.) Fusion or Cohesion. — It has already been noted that 

 the sepals, petals, stamens, or carpels may be combined in 

 place of being separate. Occasionally some of the floral 

 leaves forming a whorl are so intimately joined together that 

 there seems to be a smaller number than is really the case. 

 Thus, in flowers the corolla of which is two-lipped and consists 

 of five petals, two of the petals forming one lip may be so 

 closely fused that the double nature of the lip is not distinguish- 

 able. In this case we know that the lip represents two petals 

 either because it is opposite to one sepal or to one stamen : 

 if it represented a single petal it should alternate with two 

 sepals or two stamens (see p. 154). 



(v.) Branching or Doubling. — The floral leaves may be 

 branched or doubled so that a whorl appears to represent 

 more members than is really the case. For instance, the four 

 stamens of the staminate Hazel-flower are almost completely 

 divided down the middle, so that a careless observer might 

 imagine that eight stamens were present (fig. 132). 



In all these instances of deviations from the typical cyclic 

 flower it is possible to understand the real structure of the 

 flower, by considering the rules already given. In particular. 



