GROUP IV. PHANEROGAMIA : ANG10SPERM.E. 



505 



oligotaxy and oligomery are frequently due to suppression, in the one case of 

 one or more whorls, in the other of one or more members of a whorl, it must 

 not be assumed that this is the only possible explanation. On the contrary, 

 it is very probable that the simple structure of the flower in some plants (e.g. 

 Urticales and Amentales among Dicotyledons) is not the result of suppression, 

 but is itself typical : in other words, these flowers are probably to be regarded, 

 not as reduced, but as primitive, belonging to plants which are, it may be, of a 

 relatively low type among Phanerogams, but which are on the up-grade, and 

 not on the down-grade of organisation. The distinction of primitive from 

 reduced forms is, at 

 the present time, per- 

 haps the most im- 

 portant morphological 

 problem presented by 

 Angiosperms, for until 

 it is solved the classi- 

 fication of the group 

 will continue to re- 

 main unsatisfactory 

 and inconclusive. 



FIG. 318. Floral diagrams of Sedum RJiodiola. In the 

 staminate flower A, the (abortive) carpels are antipetalous : in 

 the carpellary flower B, the carpels are antibepalous. (After 

 Eichler.) 



The Relations of 

 Position between the 

 floral leaves and 

 those which precede them on the floral axis, can be most readily 

 made out in the case of a flower borne laterally on a main axis, 

 the pedicel springing from the axil of a bract. Where^as in most 

 Monocotyledons, the flower-stalk bears but a single bracteole or 

 prophyllum (see p. 

 493), this is gener- 

 ally situated op- 

 posite to the bract 



(Fig. 319 A), that 



i / ^"SVN \ i m ^ ,?r^\ - % \ i 



-P. 



is, posteriorly to 

 the flower ; in this 

 case the odd sepal 

 of the trimerous 

 calyx is situated 

 anteriorly. When, 

 as in most Dico- 

 tyledons, there are 

 two lateral pro- 

 phylla (usually indicated as a and /?), one on each side of the 

 flower-stalk, the position of the sepals varies according to the 



PIG. 319. Floral diagrams of Lilium bulbi/emm (after 

 Eichler) : A with normal position of the prophyllum p, op- 

 posite to the bract b: B with lateral prophyllum (p). 



