24 The Dahlia 



manner when young, but, when it is fully expanded, 

 becomes either flat or saucer shaped and a little 

 reflexed at the tip. The tendency of the ray to 

 become revolute is seen wonderfully developed in the 

 Double Cactus Dahlias. In these varieties the ray 

 while young is also folded inwards and flat, but, when 

 fully developed, is rolled backwards so that they too 

 have quite a tubular appearance. These rays are 

 also of various lengths, which make the blooms look 

 irregular. 



The florets of the Dahlia are perfect, and the tube 

 or corolla is five-lobed, and contains the five anthers 

 and one pistil with a double stigma. The five anthers 

 are untied into a tube, and the stigmas have to force 

 their way through them. In doing so the anther tube 

 is carried upwards out of the floret by the force of the 

 stigmas. After the stigmas get completely through 

 the tube, the latter is withdrawn inside the floret 

 again by the elasticity of the anther filaments. The 

 stigmas are large, and covered on their outer sides 

 with long transparent hairs about half-way down from 

 their upper ends. Further down are the papilhe of 

 the stigmatic surface proper, arranged in two rows. 

 These papillae seem gradually to change into hairs 

 as they ascend. This arrangement of the stigma is 

 similar to that of the asters. 



The seed or fruit is from a quarter to half an inch 

 in length and of a dark colour, with a few short white 

 hairs scattered over it. During the maturing of the 

 fruit the scales or bracts all close compactly together, 

 forming a complete protection to it. They are per- 

 sistent to the fruit until it is dispersed. They must 

 play an important part in the distribution of the seed, 



