Stilling Basin 



An excavation or structure below a waterfall or rapids 

 that reduces the velocity and turbulence of the current. 



Stimulus 



An influence that causes a response in an organism or 

 in a part of it. 



Stock 



(1) The parts of a plant, usually a portion of the stem 

 and the root system, to which a Scion is grafted. (2) Live- 

 stock. (3) See Standing crop. 



Stocking 



Placing animals such as deer or domestic livestock on 

 an area of vegetation. 



Stolon 



A horizontal stem on the surface of the ground where it 

 propagates vegetatively by forming new Shoots and roots at 

 the nodes, e.g., Bermuda grass, cf. Runner, Rhizome. 



Stoma (Stomate) 



A minute pore and two surrounding guard cells occurring 

 in the epidermis of leaves, young stems and fruits, and other 

 organs, through which diffusion of gases occurs. 



Stool 



The base of a plant from which shoots arise, or the base 

 including the shoots, cf. Tiller. 



Stover 



The dry, cured stems and leaves of grain crops such as 

 corn and sorghum after the removal of the grain, cf. Fodder, 

 Forage, Feed. 



Strain 



A group of organisms having distinctive attributes and a 

 common lineage which differs from other groups, but which 

 is not sufficiently distinct to form a breed or Variety. 



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