MODIFICATIONS OF THE ANDRiECIUM. 



2» 



if upon the edge, as in Convallaria (Fig. 

 117), Marginal. 



This suture may face the gynaecium, 

 when the anther is Introrse by Dehiscence 

 or away from it, Extrorse by Dehiscence. 

 It does not follow that an anther introrse 

 or extrorse in one way is the same in the 

 other. In the sagittate-horizontal »nther 



f.g.m. 



r,g.i25-. 



the sutures of the two thecae often be- 

 come continuous, the Confluent form 

 (Figs. 109 and 110). Small orifices, called 

 Pores, frequently exist at the apex, as in 

 Cassia (Fig, 118), more rarely at the base. 

 The most scrupulous care must be taken 

 to determine the exact direction in which of Scutellaria (Fig. 127) six stamens are 



thers, themselves left distinct. Coherent 

 filaments are styled Monadelphous when 

 all united (Fig. 120), Diadelphous, when 

 there are two groups, even though one of 

 them contains but one stamen, as in Gly- 

 cyrrhiza (Fig. 121), Triadelphous when 

 three, and so on. It must not be lost sight 

 of that the terms are applied similarly 

 whether the union is progressive, or the 

 result of cohesion, as in this case, or that 

 of incomplete chorisis, as in the Tilia (Fig. 

 35) and Hypericum (Fig. 30), though its 

 classificatory value is very different in the 

 two cases. The term Column, previously 



explained, is changed to Stamen-Column 

 for monadelphous stamens. The stamen- 

 column is ordinarily hollow, containing 

 the Gynaecium, but when the flower la 

 staminate it is solid, called a Synandrium, 

 The term Syngenesious is applied in a 

 special sense to coherent anthers, as in 

 Fig. 122. When, as seen in Fig. 72, the 

 anthers come together but do not actually 

 cohere, they are called conulvent. The 

 cohesion is carried only partly down the 

 filaments in the squash (Fig. 124), and in 

 the Lobelia (Fig. 125), but in the Asclepias 

 (Fig. 120) it is complete for the entire 

 organs. 



A lack of symmetry and regularity, act- 

 ing separately or together, is responsible 

 for a number of characteristic and im- 

 portant states of the androecium requiring 

 distinctive terms. In the 5-merous flower 



apical pores look in some cases, as in So- 

 lanum, where a slight difference will pos- 

 sess a specific importance. A rare form 



suppressed and the remaining four are 

 irregular, there being a similar pair of 

 each form. This form of androecium haa 



of discharge is by Valves (Fig. 119), the received the title of Didynamous. In this 



common form for the four-locellate an- 

 ther. Special mechanical contrivances for 

 aiding in the discharge of the pollen are 

 of great interest and will be mentioned 

 under Cross-pollination. 

 Cohesion is responsible for quite as 



great and important modifications of the 

 androecium as of the corolla. Here as 

 there, it may be complete, or, beginning at 

 either apex or base, it may stop at any 

 point. Pig. 71 displays the dilated bases 

 of the filaments of Styrax lightly co- 

 herent, the detection of the condition call- 

 ing for the same keen inspection as in 

 the case of the corolla. In Guarea (Fig. 

 120) the union is seen carried to the an- 



case the anthers of a pair are connivent 

 also. In that of the Mustard (Fig, 33), 

 two of the stamens have each by chorisis 

 become converted into two, these longer 

 than the undivided pair. This form is 

 styled Tetradynamous. 



No other subject connected with the 

 androecium calls for such close and dis- 

 criminating attention in connection with 

 pharmacognosy as the products of exag- 

 gerated growth and enation. No por- 

 tion of the androecium is free from their 

 effects, which apply equally to them when 

 adherent or coherent, free or distinct. 

 The simplest form of appendage to the 

 filament is that of stipuloid appendages to 



