THE ESSENTIAL OKGANS STAMENS. 



123 



most cases, leaving the anther two-celled, or Ulocular (fig. 232). 

 In some cases the internal substance of the connective is likewise 

 absorbed, producing a true unilocular anther, as in Alchemilla and 

 in Malvaceae. In other cases the four cells are retained perfect, 



Fig. 230. 



Fi>. 233. 



Fig. 230. Stamen of Erica cinerea. 



Fig. 2-31. Section of an anther, its two lobes still divided into two cells by the septa reaching 



from the connective to the sutures. 



Fig. 232. Section of a bilocular anther (the septa have been absorbed). 

 Fig. 233. Stamen of Laurus Persea, having a 4-celled anther with opercular dehiscence, and 



two lobes at the base of the filament representing divisions of a compound 



stamen. 



as in the quadrilocular anthers of Butomus, where they are parallel, 

 and of some Lauraceae, where they become oblique so that the 

 summits are all turned towards the face. The dimidiate unilocular 

 anthers of Gomphrena and Salvia are so called from being only 

 halves of anthers in which one lobe is abortive or suppressed. 

 Anomalous one-celled anthers occur in Poly gala. The unilocular 

 lateral anthers of the diadelphous stamens of Funiariaceae are 

 dimidiate. 



Dehiscence. When the anthers are mature, the cells or loculi 

 open and discharge the pollen. This dehiscence takes place in 

 different ways ; it may be 'sutured, porous, or opercular. Sutural 

 dehiscence is the opening of the walls by splitting down vertically 

 at the sutures, which may be extrorse, introrse, or lateral (see 

 p. 126). A transverse slit is formed in the unilocular anther 

 of Alchemilla, in Lavandula, and in Lemna. Porous dehiscence 

 is where definite orifices are formed at some point of the wall 

 of the loculus, as at or near the summit in Solanum, Ericaceae 

 (figs. 229, 230), &c. Opercular dehiscence results from the partial 

 separation of a portion of the wall of the loculus, in the form of 

 a kind of lid, as in the Berberry, where the front of each cell splits 

 off at the sides and base, and turns back as if hinged at the top. 



