XII 

 WAYSIDES AND WASTES IN SUMMER {Continued) 



Composite Flowers 



There are so many flowers of the order Compositcv in bloom by the 

 wayside and on waste ground during the summer months that we 

 devote a chapter entirely to them. 



This group is the largest of the natural orders, and is computed 

 to contain about a tenth of all the known flowering plants. The 

 chief distinguishing characteristic of the order is the arrangement 

 of the flowers into crowded heads, each consisting of a number 

 of Uttle flowers or florets that are sessile on a common receptacle, as 

 in the case of the Daisy, the Dandelion, and the Thistles. 



The florets of each head or capitulum are generally arranged 

 into two welLdefined sets — the florets of the disc, occu23ying the 

 centre ; and the florets of the ray, spreading more or less in a 

 radial manner from the edge of the disc. These two sets are often 

 of difl^erent colours, as in the Daisy, where the disc florets are of a 

 deep yeUow, while the ray florets are white or pink. 



In some of the Composites aU the florets of each head are perfect, 

 while in others some are perfect and some imperfect. Then, as 

 regards the latter, they may be staminate or male florets, with no 

 pistil ; pistillate or female flowers, with no stamens ; or neuter 

 florets, possessing neither stamens nor pistil. In some few cases 

 all the florets of one head are staminate, while the pistillate florets 

 alone form other heads ; and in these instances the two kinds 

 of heads may be found on one plant, or only one kind may exist 

 on the same plant. In all cases the capitulum is surrounded by 

 one or more whorls of bracts which are often closely overlapping. 



The florets seldom possess a distinguishable calyx, but there 

 is sometimes an indication of the presence of five sepals ; in many, 

 however, the calyx is represented by a whoi'l of haii-s on the summit 



