Shinnery 



Vegetation consisting of dwarf oaks as dominants, espe- 

 cially in sandy areas in the southern Great Plains. 



Shipworm 



An animal of the Lamellibranchiata (clams), especially 

 Teredo navalis which burrows in submerged wood. 



Shock Disease 



The deterioration in overcrowded populations of an or- 

 ganism in which the activity of the Endocrine glands (q. v.) 

 is abnormal and the general condition and viability of the 

 animals are reduced, which may result in a rapid decline 

 (crash) in the number of individuals. 



Shoot 



The stem and leaves of a plant taken collectively, cf. 

 Sprout. 



Shore, Depositing 



The addition of sand, silt, and clay, or the removal of 

 rock, to the land adjacent to a body of water by the action 

 of water or wind. 



Short-day Plant 



A plant that blooms when periods of light are short and 

 periods of darkness are long, e.g., chrysanthemum, cf. 

 Photoperiodism. 



Short Grass 



Grasses that grow only a few inches high, particularly 

 blue gramagrass and buffalograss. cf. High grass, Medium- 

 height grass. 



Shrub 



A perennial woody plant that differs from a tree by its 

 low growth and the possession of several stems arising from 

 the base. 



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