30 



INTRODUCTION TO BOTANY 



other common plants root readily in water and grow for a 

 long time if supplied only with ordinary river or well water. 

 The number of kinds of seed plants which float, and therefore 



FIG. 22. Aerial roots (brace roots) of corn. Reduced 



Note that the series a and 6 began as aerial roots, but later entered the ground 



and then developed many small branches. Those at c, if not checked by frost, 



would eventually also have reached the ground 



