GROUP IV. — PHANEROGAMIA : ANGlOSPERMiE. 



505 



oligotaxy and oligomery are frequently due to svppression, 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 doion-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 diasrams of Sedimi Rhodiola. In the 

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

 Position between the ^^® cai-pellary flower B, the carpels are antisepalous. (After 

 nil 7 Eichler.) 



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- O O 



ally situated op- 

 posite to the bract 

 (Fig. 319 A), that 

 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 



-p. 



Fig. 319. — Floral diagrams of Lilium hxilhiferxim (after 

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

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



