INTRODUCTION 13 
or not those conditions have demanded a different 
habit. 
The tree habit conduces to an absence of a ground 
flora in many cases, such as in Beech woods. Next 
to the tree habit, the shrub or bush type is most 
successful. Both of these dominate the dispersal of 
plants that seek the shade. For there are shade 
plants and sun plants. 
Under scrub or bush, or amid it, the sun plants 
can thrive where under trees they cannot. Scrub 
and bush are deteriorated forest land. And it is 
easy to see that the plants of the open, except 
alpines and cliff and aquatic plants, have come to 
adopt their present habit and habitats after being 
subjected to this intermediate scrub stage. The 
scrub, though dominant and wide-spreading, allows 
the herbaceous type of plant to struggle toward the 
light by adopting a pyramidal habit. Many plants 
that live under the shade of hedge or woods have 
this pyramid habit, being broader at the base and 
gradually narrowed upwards. 
The rosette habit is a stage further, the plant 
having a rosette of radical leaves and a straight, 
erect stem. 
~ Lastly, there is the grass habit—a third dominant 
_ stage. By having this slender habit large numbers 
of the same species can occupy the minimum of 
ground and still reach the sunlight amongst the 
other surrounding plants, and perform the necessary 
functions of life. 
