498 



PAKT 111. THE CLASSIFICATION OF PLANTS. 



if radii be drawn from the centre of the flower, it will be seen 

 that the stamens are opposite to the sepals and the carpels to the 

 petals, or more briefly, that the stamens are antisepalous and the 

 carpels are antipetalous. This is not, however, a case of direct 

 superposition, since the corolla intervenes between the androecium 

 and the calyx, and the androecium intervenes between the gynce- 

 ceum and the corolla. 



There are, however, certain cases in which this law of alternation 

 does not prevail, in which, that is, the members of successive 

 whorls are directly superposed. For instance, the (45) stamens 

 are directly antipetalous in several natural orders (Primulaceee, 

 Myrsinaceae, Sapotacea3, Plumbaginacese, Ampelidacese, Rham- 

 iiaceae) ; again, in some Campaiiulacese (e.g. Campanula Medium, 

 Fig. 312, Michauxra) the (5) carpels are directly superposed on 

 the stamens. 



The Floral Diagram. These various arrangements of the floral 



FIG. 311. -Floral diagram (ground-plan) 

 of an acyclic flower, with f divergence in 

 the calyx, corolla, and androecium (ter- 

 minal flower of Berberis : after Eichler). 



FIG. 312. Floral diagram of Cam- 

 panula Medium : the five carpels are 

 directly superposed on the stamens. 

 (After Eichler). 



leaves, like those of the foliage-leaves, are most clearly repre- 

 sented by means of diagrams (see p. 25). In & floral diagram, the 

 calyx lies externally, and the gynasceum, as being the uppermost 

 series of organs (even in epigynous flowers) lies most internally. 

 In order to be able readily to distinguish the various series, 

 symbols are used which recall some peculiarity of their form : 

 thus the midrib of the sepals is indicated, and, in the case of 

 the stamens, the anthers. 



If only such relations of position as can be actually observed in 

 a flower are indicated in the diagram, a simple empirical diagram 

 is the result. If, however, the results of the investigation of the 

 development of the flower and of the comparison of it with others 



