100 



THE STAMENS, OB AKDRCECIUM. 



AndrcEoium (and gynoedum) of Frankenia (after Peyer). 887, Stamen (adnate) of morning- 

 glory. 338, Same enlarged, with pollen grains discharged ; /, filament ; a, a, anther, 2-lobed ; c, 

 top of the conneotile. 839, BanuncalDS. 340, Same, cut transversely. 841, Iris cut transversely 

 <extrorse). 842, Amaryllis, versatile. 843, Larkspur, innate, 844, Same, cut. 



f 493. The filament (Jilum, a thread) is the stalk supporting the 

 anther at or near its top. It is ordinarily slender and filiform, yet 

 firmly sustaining itself with the anther in position. Sometimes it is 

 capillary and pendulous with its weight, as in the Grasses. 

 p 494. The anther is regularly an oblong body at the summit of the 

 filament, composed of two hollow parallel lobes joined to each other and 

 to the filament by the connectile. In front of the conneotile, looting 

 toward the pistil, there is usually a furrow ; on its back a ridge, and on 

 the face of each lobe a seam, the usual place of dehiscence or opening, 

 all running parallel with the filament and connectile. 



The stamen, as thus described, may be oonaidered regular or typical iu form, and 

 is well exemplified in that of the buttercup (Fig. 339). But the variations of struc- 

 ture are as remarkable here as in other organs, depending on circumstances like the 

 following — 



495. AiTAOHMEKT OF FILAMENT TO ANTHEB. This may oGour in three ways. 

 The anther is said to be innate when it stands centrally erect on the top of the fila- 

 ment, adnate whan it seems attached to one side of the filament, versatile when 

 connected by a single point in the back to the top of the filament. 



496. Dehiscence, or the modes of opening, are also three, viz., valvular, where 

 the seam opens vertically its whole length, which is the usual way ; porous where 

 the cells open by a chink or pore usually at the top, as in Ehododeudron and po- 

 tato ; opercalAr when by a lid opening upward, as in sassafi'as, berberis. (346.) 



49Y. The FAoma of the anther is also an important character. It is introrse 

 when the lines of dehiscence look toward the pistU, as in violet ; extrorse whMi 

 they look outward toward the corolla^ as in Iris. 



498. The connectile is usually a mere prolongation of the filament, terminating, 

 not at the base, but at the top of the anther. If it fall short, the anther wiU be 

 emarginale. Sometimes it outruns the anther and tips it with a terminal append- 

 age of some sort, as in violet, oleander, Paris. Again, its base may be dilated into 

 spurs, as in two of the stamens of violet. 



499. Dimidiate anther. If the conneotile be lateraEy dilated, as we see gra- 

 dually .done in the various species of the Labiate Order, the lobes of the anther 

 will be separated, forming two dimidiate anthers (halved anthers) on one filament, 

 as in sage, Prunella. Such are, of course, l-celled. (851.) 



