Adventive 



A plant growing spontaneously, not native, ephemeral or 

 not spreading appreciably. 



Aelophilous 



Refers to dissemination by wind. 



Aeolian 



Refers to the wind, or to soil materials which have been 

 moved by the wind or are subject to such movement. 



Aeration 



The processes by which air and other gases in a medium 

 are renewed or exchanged. 



Aerobe 



An organism capable of living only in the presence of 

 free oxygen. 



Aerenchyma 



Tissue with thin-walled cells and large air spaces, espe- 

 cially common in aquatic plants. 



Aerial Photograph 



A vertical or oblique photograph taken from the air. 



Aerobic 



Refers to life or a process occurring only in the presence 

 of free oxygen. See Aerobe. 



Aerobiosis 



Life in the presence of free oxygen in the medium. 



Aerophyte 



See Epiphyte. 



Aeroplankton 



Microorganisms floating in the air, cf. Plankton. 



Aerotaxis 



Involuntary response of an organism to a gas, such as 



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