100 



THE STAMENS, OR ANDRCECIUM. 



AndroBclmn (and gynoscium) of Frankocia (after Peyer). S37, Stamen (adnatc) of morning- 

 glory. 333, Same enlarged, with pollen grains discharged ; / filament ; a, a, anther, 2-lobed ; c, 

 top of the conneetile. 839, Banunculus. 340, Same, cut transversely. 84), Iris cut transversely 

 (extrorse). 342, Amaryllis, versatile. 843, Larlispur, innate. 344, Same, cut. 



493. The filament (filum, 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 

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



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 conneetile. In front of the conneetile, looking 

 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 conneetile. 



The stamen, aa thus described, may be con3idered regular or typical in form, and 

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

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

 following — 



495. Attachment of filament to anther. This may occur in three ways. 

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

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

 connected by a single point in tlxe 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 Rhododendron and po- 

 tato ; opercular when by a lid opening upward, as in sassafras, berberis. (346.) 



497. The facing of the anther is also an important character. It is introrse 

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

 they look outward toward the coroUa, as in Iris. 



498. The conneotilb 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 will be 

 emarginate. 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 conneetile be laterally dilated, as we see grar 

 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, PranelLa. Such are, of course, l-celled. (351.) 



