338 SYSTEMATIC BOTANY 



CHARACTERS OF THE COMPOSITE 



All these plants are alike in the florets being im- 

 perfect by the non-development of the calyx, and 

 massed into a head with an involucre below ; in the 

 inferior ovary, which ripens into an achene ; in the 

 syngenesious anthers with connective produced at the 

 top ; and in the style with its two stigmatic branches. 



There is in nearly all cases no difficulty at all in 

 recognizing any member of this very well-marked 

 family. Most have alternate leaves though one or 

 two have them opposite. A comparatively few only 

 have scales between the florets, the receptacle being 

 generally naked. 



In many genera there develop at the top of the 

 achene where the calyx should be, a circle of hairs, 

 called the pappus, which makes it buoyant and easily 

 carried by wind (p. 261). In some a few scales or 

 sharp points are developed, in others nothing at all. 



The nature of the flower-heads, whether all the 

 florets are the same and tubular, or some tubular 

 with rays of ligulate ones round, or again all ligulate, 

 as in the instances given above, are points of im- 

 portance ; as also are the presence or absence of scales 

 between the florets, and of a pappus on the fruit, and 

 its nature whether simple as SENECIO, or feathery as 

 the Dandelion. The anthers may be produced in tails 

 at the base as in * CENTRATHERUM and VERNONIA, 

 or be rounded as in the Sunflower, ASTER and 

 * AGERATUM. The arms of the style may be short 

 or long, blunt or pointed. The bracts of the involucre 

 may be all of one length and in one circle as in EMILIA 



