ESSENTIAL ORGANS. STAMENS. 



191 



name of the Disk, or separate prolongations from the filament itself. 

 In fig. 313, a represents such a staminiferous appendage found 011 

 the inner side of the base of the filament, f, 

 which is hence called appendiculate, or some- 

 times strumose (struma, a swelling). The pro- 

 cesses noticed in the Boraginaceas as modified 

 petals (fig. 312 a), may be considered external 

 appendages of the filaments, the stamen being 

 regarded as the lamina of a petal. 



399. Filaments are usually articulated to 

 the torus, and the stamen falls off after fertili- 

 zation; 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 An- 

 droecium may unite, forming a tube round the pistil (fig. 307 e), or 

 a central bundle 

 when the pistil is 

 abortive (fig. 314, 

 1), the stamens be- 

 coming monadelphous 

 (povo;, one, and aSsX- 

 <poV, brother), as oc- 

 curs in Geranium (fig. 

 307), Malva, Hibis- 

 cus, and Jatropha 

 Curcas (fig. 314, 1); 

 or they may unite so 

 as to form two bun- 

 dles, the stamens be- 

 ing diadelphous (d<?, 

 twice), as in Poly gala, 

 Fumaria, and Pea; 

 in this case the bun- 



314,1 



314,2 



Fig. 312. Stamen of Borago officinalis. /, Appendiculate filament, o, Appendage prolonged 

 in the form of a horn-like process. I, Lohes of the anther. 



Fig. 313. Stamen of Zygophyllum fabago. /, Filament, connected with a broad scaly ap- 

 pendage, a. 



Fig. 314. Male or staminiferous flower (1), and female or pistilliferous flower (2), of Jatropha 

 Curcas. c, Calyx, p, Corolla, , 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 

 three bifid styles at its summit, a, Small glandular appendages alternating with the divisions 

 of the corolla. Above each of the flowers is a diagram representing the order In which the dif- 

 ferent parts of the flower are arranged. In diagram 1 are represented five parts of the calyx, 

 five of the corolla, two rows of stamens, five in each. In diagram 2, the staminal rows arc abor- 

 tive, and there are three carpels, forming the pistil, in the centre. 



