XXVi INTRODUCTORY LESSONS, 
woes Bis Calyx tube. 
Sacavendeeinanaeaae Calyx lobes. 
tf Is. 73, A flower of Whipplea, magnified, cut down 
a Difid petats through the center, showing the partly interior 
72 ovary aud the iutrorse anthers. 
to a third of the length. Irregular flowers are frequently 
Bilabiaie or Two-lipped, as shown in the figures a and ¢ 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 
used to designate the calyx and corolla taken together. It is 
Wf mostly used in describing endogenous flowers (Figs. 70, 71). 
Stamens may grow upon the receptacle (Hy pogynous, 
Fig. 69), upon the calyx (Perigynous, Fig. 68), 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. 68). Staminodia are antherless or abortive stamens (see longer sta- 
mens in Fig. e, p. 8). Anthers usually consist of two cells, which are 
filled with 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 by 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 
