XXVI 



I^'TRODUCTORY LESSONS. 



73. A flower of WTiipplca, magnified, cut down 

 tlirough tbe cen'er, showing the partly inlei-ior 

 ' -^ ovary and the iutrorse anthers. 



to a third of the length. Irregular flowers are frequently 

 Bilabiate or Two-lipped, as shown in the figures a and c on 

 p. 11, and the figures on p. 88b. "When the tube of a corolla 

 is slender, and the regular or irregular limb is small or want- 

 ing, the flower is said to be Tubular. The term Perianth is 

 ^4^. ' used to designate the calj-x and corolla taken together. It is 

 "^ mostly used in describing endogenous flowers (Figs. 70, 71). 

 Stamens may grow upon the receptacle (I-Iypog3^nous, 

 Fig. G9), upon the calyx (Perigynous, Fig. G8), upon the 

 corolla (Fig. 67), or upon the pistil. Stamens are often 

 united by their filaments so as to form tubes (Fig. 74) or 

 bundles; or the anthers are joined, as in the Sunflower or 

 Thistle. Sometimes there are two kinds of stamens in the same flower 

 (Fig. 6S). Staminodia are antherless or abortive stamens (see longer sta- 

 mens in Fig. e, p. 8). Anthers usually consist of two cells, which are 

 filled Avith Pollen. If the upper end of the filament lies exactly between 

 the anther cells, the anther is Innate. An Adnate anther is attached by 

 one side to the filament (Figs. 67, 68). A Versatile anther is attached be- 

 tween its ends b}' one side to the tip of the filament (Figs. 71, 72). The 

 pollen usually escapes from slits in one side of the anther, as shown in 

 Fig. 69. This side, which in an adnate or versatile anther, is opposite 

 the filament, is called the face of the anther. "When the anther faces 



