Such woods are unfitted to resist shock or sudden application of load.
The measure of the stiffness of wood is termed the ~modulus of elasticity~ (or _coefficient of elasticity_).

It is the ratio of stress per unit of area to the deformation per unit of { unit stress } length.

{ E = -- ----------- } It is a number indicative of { unit strain } stiffness, not of strength, and only applies to conditions within the elastic limit.

It is nearly the same whether derived from compression tests or from tension tests.
A large modulus indicates a stiff material.

Thus in green wood tested in static bending it varies from 643,000 pounds per square inch for arborvitae to 1,662,000 pounds for longleaf pine, and 1,769,000 pounds for pignut hickory.