258 



PLANT STRUCTURES 



The only advanced character in the flowers as described 

 above is the syncarpous pistil, but in the great allied pepper 

 family (Piper acece) of the tropics, with its one thousand 

 species, and most nearly represented in our flora by the 



FIG. 242. Ovule of hornbeam (Carpinus), showing chalazogamy: m, the micropyle; 

 pt, the pollen tube, which may be traced to its entrance into the embryo-sac at its 

 antipodal end, and thence upward through the sac toward the egg. After MARY 



EWART. 



lizard-tail (Saururus) of the swamps (Fig. 195), the flowers 

 are not merely naked, but also apocarpous, and the whole 

 structure is much like that of the simplest Monocotyle- 



