STRUCTURAL BOTANY. 



[40. 



may occur in three ways. The anther is said to be innate when it stands cen- 

 trally erect on the top of the filament; adnate when it seems attached to one 

 side of the filament ; versatile when connected to the top of the filament by a 

 single point in the back. 2d, The modes of Dehiscence, or 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 Potato ; opercular, when by a lid opening up- 

 ward, as in Sassafras, Berberis (92). 3d, 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 corolla, as 

 in Iris. 4th, The connectUe is usually a mere prolongation of the filament, ter- 

 minating, 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 appendage of some sort, as in Violet, Oleander, and Paris. Again, 

 its base may be dilated into spurs, as in two of the stamens of Violet. 5th, If 

 the connectile be laterally dilated, as we see gradually done in the various 

 species of the Labiate Order, the lobes of the anther will be separated, form- 

 ing two dimidiate (halved) anthers on one filament, as in Sage and Brunella. 

 Such are, of course, 1-celled (96). 

 P 



9r> 



Peculiar forma of stamens. 89, Pyrola rotundifolia ; p, dehiscence by pores at top. 90, Vaccinium 

 uliginosum ; p, dehiscence. 91. Berberis aquifolium, anthers opening (92) by valves upward. 93, Anther 

 of Violet, introrse, with an appendage at top. 94, Oleander, sagittate, appendaged. 95, Catalpa, lobes of 

 anther separated. 93, Sage, lobes of anther widely separated, on stipes ; b, barren lobe without pollen. 

 97, Malva, anther 1-celled. 98, Ephedra (after Peyer), anther 4-celled. 



115. The cells of the anthers are at first commonly 

 four, all parallel, becoming two only at maturity. In 

 some plants the four are retained, as in the anthers of 

 Ephedra (98). In others, as Mallows, all the cells 

 coalesce into one (97). 



116. Appendages of many kinds distinguish the stamens of different spe- 

 cies. In the Ericaceae there are horns, spurs, tails, queues, etc. In Onions and 

 Garlic, the filament is 2 or 3 forked, bearing the anther on one of the tips. 

 Sometimes a pair of appendages appear at base, as if stipulate. It is often 

 conspicuously clothed with hairs, as in Tradescantia. (See 89-94.) 



117. Staminodia, or sterile filaments with abortive anthers or none, occur 

 singly in many of the Figworts and Labiates, or in entire whorls next within 

 the petals, alternating with them, as in Loose-strife. The curious fringes of 

 the Passion-flower are regarded as composed of staminodia (112). 



