N 



Nanism 



The dwarfed appearance of plants, as at tree-line in 

 mountains. 



Nanophanerophyte 



A subdivision of the Phanerophytes (q.v.) in Raunkiaer*s 

 life-form classification, comprising shrubs 0.25 to 2 meters in 

 height. 



Nanophyll 



See Leaf-size classes. 



Nannoplankton 



Very minute Plankton (q. v.), those that pass through 

 meshes of a No. 20 silk bolting cloth (0.03 to 0.04 mm.). 



Nastic Movement 



A response in plants caused by a diffuse stimulus (not 

 received from a definite direction) or when the response to 

 a diffuse or lateral stimulus is determined exclusively by the 

 irritable organ, e. g., drooping of the leaves of Mimosa 

 pudica when it is touched, cf. Tropism. 



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