CHAEACTBRS OP MONOCOTYLBDONS, , 87 



endogenous, and the plants composing the group are called 

 Endogens, as well as Monocotyledons. The term 

 Endogen, however, is used in quite a different sense by 

 some recent botanists, and is discarded by them as a 

 synonym for monocotyledon, as having been given originally 

 under a misconception as to the true mode of growth of 

 the wood in stems of this kind. We shall explain more 

 fully the structure of exogenous and endogenous stems 

 when we come to speak of the minute structure of plants 

 in a subsequent chapter. 



120. The typical flower of the Monocotyledons is that 

 of the Lily ; it consists of five whorls, two belonging to the 

 perianth, two to the anthers, and one to the pistil. Other 

 flowers of the group, as we have ^een, exhibit departures 

 from the type, chiefly in the suppression of wJiorls or 

 parts of whorls. Thus in the Iris one whorl of stamens 

 is suppressed. In this plant, also, the ovary is inferior. 

 In the spadiceous plants the perianth is suppressed, and 

 m the Grasses there may be suppression in all the whorls. 



CHAPTER XVI. 



EXAMINATION OF CONIPEEOUS PLANTS — WHITE PINE — 

 GROUND-HEMLOCK. 



121. The eone-bearing trees are so striking and important 

 :i featare in Canadian vegetation that even an elementary 

 -T/ork like the present would be incomplete without a 

 notice of them. They form, besides, a very distinct group 



