482 



NATURAL HISTORY OF PLANTS. 



equal number of stamens alternating with the perianth-leaves and in- 

 serted a little below them ; each consists of a short filament and an 

 introrse two-celled anther of longitudinal dehiscence. 1 The gynasceum 

 is free, with a one-celled ovary which tapers into a slender style, passing 

 through the narrow opening of the receptacular pouch, and traversed 

 by a longitudinal groove down the placentary edge. Near the top of 

 the style the edges of this groove are thickened, and turn outwards to 

 form two thick elongated lips covered with stigmatic papillae. In 

 the bottom of the ovary-cell is a subcentral placenta, whereon is in- 

 serted a nearly erect anatropous ovule, whose micropyle is turned 

 down next the placenta, 2 the thickened base of which often furnishes 

 it with an obturator. 



Elaagnus angustifolia. 



Fig. 280. 



Longitudinal section 

 of flower (|). 



Fig. 281. 

 Diagram. 



Fig. 282. 



Fruit in its 

 indusiuin. 



Fig. 2S3. 



Longitudinal sec- 

 tion of fruit (§). 



Fig. 284. 

 Stone. 



After flowering the receptacle grows and forms a complete 

 indusium around the fruit, which is often long crowned by the 

 remains of the perianth and androceum (figs. 282, 2S3). The walls 

 of this indusium behave as in a true drupe. Its deep layers become 

 hard and woody, forming a sort of stone (fig. 284 s ). Outside of this 

 the tissues grow succulent as in a sarcocarp, and are covered exter- 

 nally by the membranous epidermis cloaked in peltate hairs. The 

 true fruit, lodged in this thick pouch, is an achene with a membra- 



1 In IE. angustifolia the pollen-grains are tri- 

 angular, much flattened, with little papillae on 

 the angles. (H. Mohl, in Ann. Sc. Fat., ser. 2, 

 iii. 314.) 



- The ovule has two coats. When adult its 

 raphe is neither turned towards or away from the 

 placenta, hut is well on one side (fig. 281). 



3 It is formed of vertically elongated fibres 

 incrusted with woody matter. The internal 

 epidermis of the receptacle bears long cylindrical 

 hairs, which persist even after the fruit is ripe. 

 The stone is traversed all the way down by 

 more or less regular grooves, separated by 

 rough projecting ribs. 



