The Environment of Plants 151 



advances, we are able to relate more and more of the effects 

 that we observe in plants to definite factors in their environ- 

 ment. The farmer, gardener, or forester is often able to use 

 this knowledge in making the environment more favorable for 

 the plants which he grows. 



Subdivisions of botany. Three of the great subdivisions of 

 botany are morphology, physiology, and ecology. The study 

 of the structures of plants is plant morphology (Greek morphos, 

 form, and logos, study of). The study of the processes of 

 plants such as transpiration and photosynthesis is plant 

 physiology (Greek: physis, nature, and logos, study). The 

 study of plant structures and processes in relation to the en- 

 vironment, or as they are modified by the factors that make up 

 the environment, is called ecology (Greek : oikos, home, and 

 logos], or ecological botany. Since the environment deter- 

 mines what plants can live in a particular place, ecology in- 

 cludes also the study of the distribution of plants on the 

 earth's surface and attempts to account for that distribution. 

 For this reason the environmental factors that affect plants 

 are also spoken of as ecological factors ; and the changes in 

 structure that adjust plants to particular habitats may be 

 called ecological modifications. 



PROBLEMS 



1. What is the principal factor that limits the growing of oranges in this coun- 

 try to Florida and southern California? 



2. Why are beans planted a month later than peas? 



3. What environmental factor determines that melons and squashes should 

 not be planted until late spring? 



4. What factors in the environment make it necessary to spray potatoes ? 



5. What is the principal factor limiting the production of crops on the Western 

 plains? 



6. Why are plants absent from the larger sand dunes? 



