GROUP IV. — PHANEROGAMIA : ANGIOSPERMj;. 



523 



7f 



T 



'J 



The inferior ovary of epigynous flowers (see p. 495) is rarely 

 monomerous, that is to say, the cavity formed by the axis is but 

 seldom closed by one carpel only : it is commonly polymerons, but 

 it may be either unilocular or multilocular ; in the latter case, the 

 margins of the carpels grow down along the internal surface of the 

 cavity. 



In some bases the axis is prolonged between the carpels, con- 

 stituting a carpophore, as in the Geraniaceee and Umbelliferse 

 (Fig. 341). 



The Style (Figs. 335 and 337) is the prolongation of the upper 

 part of the carpel : it is commonly a slender cylinder, but some- 

 times it is leafy and petaloid (e.g. Iris). Monomerous ovaries 

 have but one style ; polyraerous ovaries have as many styles as 

 there are carpels, which may cohere throughout 

 their whole length, or at their lower parts only, 

 the upper parts remaining distinct ; or they may 

 remain quite free, and they may even branch. 

 The style originally arises from the apex of the 

 ovary, but it is frequently displaced forwards, by 

 the vigorous development of the dorsal portion of 

 the carpel, on to the inner side, so as to appear 

 to be a prolongation of the floral axis (gynobasic 

 style) : this is conspicuous in the Boraginaceae 

 and Labiatoe, where it is surrounded by the four 

 rounded loculi of the ovary which have been 

 already mentioned (p. 622). The style is some- 

 times very short, and appears only as a constric- 

 tion between the ovary and the stigma, as in the 

 Poppy. In some rare cases it is hollow, but it is 

 usually filled with a loose tissue, called conducting 

 tissue, through which the pollen-tube can easily 

 penetrate. 



The Stigma (Figs. 335 and 337 n) is usually terminal, but it may 

 be lateral {e.g. Iris) ; it is distinguished by being covered with 

 papilla), or frequently with hairs, and by the secretion of a sugary 

 fluid which retains the pollen-gi*ains which fall upon it, and 

 which promotes the development of the pollen-tubes. The stigma 

 is often evidently distinct from the style, appearing as a lobed 

 expansion ; in other cases it seems to be merely a portion of the 

 style at its end or sometimes on its side. In Papaver it is a 

 sessile disk-shaped expansion on the upper surface of the ovary ; 



Fig. 337.— Gy- 

 nspcenm of the 

 Lily : / ovary ; g 

 style ; n stigma 

 (nat. size). 



