218 



ESSENTIAL ORGANS — STAMENS. 



inner side of the base of the filament, /, whicli is hence called appen- 

 diculate, or sometimes strumose (sti-uma, a swelling). The processes 

 noticed in the Boraginacese as modified petals (fig. 344 a) may be 

 considered external appendages of the filaments, the stamen being 

 regarded as the lamina of a petal. 



Filaments are usually articulated to the thalamus or torus, and 

 the stamen falls off after fertilisation ; but in Campanula and other 

 plants they are continuous with the torus, and the stamen remains 

 persistent, although in a withered state. Certain changes are pro- 

 duced in the whorl of stamens by adhesion of the filaments to a greater 

 or less extent, while the anthers remain free ; thus, all the filaments 

 of the androecium may unite, forming a tube round the pistil (fig. 338 

 «), or a central bundle when the pistil is abortive (fig. 346, 1), the 



Fig. 346, 1. 



Fig. 346, 2. 



Fig. 347. 



stamens becoming monadelphous {/Lovog, one, and &iik(pli, brother), as 

 occurs in Geranium (fig. 338), Malva, Hibiscus, and Jatropha Curcas 

 (fig. 346, 1) ; or they may unite so as to form two bundles, the 

 stamens being diadelphous [dls, twice), as in Polygala, Fumaria, and 



Fig. 346. Male or staminiferous flower (1), and female or pistilliferous flower (2), of 

 Jatropha Curcas. c. Calyx, p, Corolla, e, Stamens united by filaments occupying the 

 centre in flower 1, in consequence of the suppression of the pistil, p, Pistil in flower 2, 

 composed of ovary, o, with tluee bifid styles at its summit, a, Small glandular appendages 

 alternating with the divisions of the corolla. Above each of the flowers is a diagram repre- 

 senting the order in which the different pai-ts of the flower are arranged. In diagram 1 are re- 

 presented five parts of the calyx, five of the corolla, two rows of stamens, five in each. In 

 diagram 2, the staminal rows are abortive, and there are three carpels forming the pistil, in 

 the centre. Fig. 347. Triadelphous stamens of Hypericum ffigj'ptiacum surrounding .the 

 pistU, 0. //, United filaments forming columns, e e. Anthers free. The outer envelope 

 of the flower has been removed, the essential organs alone being left. 



