which is resistant to leafhoppers replacing Russian thistle 

 and mustards which are susceptible to the insect, cf. Suc- 

 cession. 



Reproduction, Vegetative 



Propagation of a plant by stems, roots, or other asexual 

 organs, e.g., strawberry plant increasing in number by means 

 of runners, cf. Propagate, Sexual reproduction, Asexual 

 reproduction, Apomixis. 



Reproductive Isolation 



The separation of populations or organisms so that inter- 

 breeding cannot occur. 



Reproductive Potential 



The maximum rate of increase in numbers of individuals 

 of a species or a population under the most optimum condi- 

 tions, in contrast to the actual reproduction obtained under 

 existing conditions, cf. Biotic potential, Environmental 

 resistance. 



Reptile 



An animal in the class Reptilia of the subphylum Verte- 

 brata. e.g., snakes, crocodiles. 



Roseau 



The group of meteorological stations operating under a 

 common direction or in the same territory. 



Residual Soil 



A kind of soil formed in place by the disintegration and 

 decomposition of rocks and the consequent weathering of 

 the mineral materials, cf. Alluvium. 



Residual Stand 



See Second growth. 



Resistance 



The capacity of an organism to remain relatively un- 

 affected by insects, disease-causing bacteria or fungi, or 



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