THE FLOWER 



FIG. 89. a. Transverse section of young 

 ovary ( x 70) ; b, portion of its wall 

 ( x 260). 



on which the pore is found and are utilised in the development of the 

 pollen-tube ; they are not found in the immature pollen-grain. 



The gynaecium consists of a single median carpel, with an obovate 

 or obconical ovary, slightly trilobed in transverse section and flattened on 

 the ventral side. At the time of an- 

 thesis it measures i mm. long and is 

 about the same diameter across the 

 upper portion. 



Its sides are smooth, but the broad 

 apex is clothed with numerous long 

 finely-pointed unicellular hairs about 

 io/i in diameter and varying in length 

 from -16 mm. to i mm. 



The wall of the ovary averages -35 mm. in thickness. It consists of 

 delicate loosely-packed parenchyma 10-16 cells across, clothed on the 

 outside with a well-defined epidermis, its inner surface being lined with 

 a similar but thinner epidermal layer. Running 

 longitudinally through it are two very fine lateral 

 and one dorsal vascular strand, each of the former 

 possessing three to six delicate tracheae, the latter 

 usually only one (Fig. 89). 



From the tip of the ovary arise two terminal 

 styles 3-4 mm. long, which curve outwards when 

 flowering occurs. Each has a central tapering 

 column from which are given off So-ioo delicate 

 stigmatic branches -8 to i -5 mm. long ; the latter 

 extend to the base on the inner side, but only 

 about one-third of the way down the outer side of 

 each stylar column. 



The two lateral vascular bundles of the ovary 

 are continued some distance into the styles. 



Each delicate stigmatic branch is composed of 



210) and Iran--. four rows of elongated cells about 250 /t long and 



S-io /i in diameter. They are joined throughout 



their whole length except at the upper end of each cell, which is free, 

 and curved outwards into a bluntish point 24-30 /x long (Fig. yo). 



The angles between the tree ends of these cells and the sides of the 

 branches form convenient resting-places for the pollen-grains shed from 

 the dehiscent anther at the time of flowering. 



Within the ovary is a single sessile anatropous ovule attached to a 

 broad placenta on the inner ventral surface of the ovary (Fig. <>i).' It 

 is about -5 mm. long am! 4 nun. broad, and possesses two integuments ; 

 the outer one, which is disintegrated before the seed is ripe, is shorter 



Fu;. yo. I'ppcr part of 

 stiifrnatic branch ( 



