- The natural order Oleaceae includes a number of species of the genus Fraxinus or ash, whose timber is characterised by good strength elasticity, toughness, stiffness and hardness, allied to relatively light weight. The following are the principal species found in North America:
- Black ash Fraxinus nigra
- Green ash Fraxinus pennsylvanica
- White ash Fraxinus americana
- BLACK ASH An eastern species; it occurs mainly from the Gulf of the St Lawrence to Manitoba.
- GREEN ASH Found in fairly limited quantities from south-eastern Quebec throughout southern Ontario to eastern Saskatchewan and also in the southern states of America to the Mississippi River.
- WHITE ASH Occurs in Canada from Nova Scotia to south-western Ontario, and in America from New England, the Middle Atlantic and Central States.
- BLACK ASH A slender, medium sized tree reaching a height of 18m to 21 m growing in swamps and by rivers.
- GREEN ASH A small tree, some 12m to 15m in height.
- WHITE ASH The tree reaches a height of 15m to 18m or a little more, and a diameter of about 0.75m.
- BLACK ASH The timber is greyish-brown to brown in colour, darker than that of white ash, (F. americana} and inferior to that timber in general strength properties and lighter in weight, about 560 kg/m³ when dried. A certain amount of this species is used for interior trim and fittings It takes a good finish.
- GREEN ASH Produces timber similar to American white ash in appearance, but inferior to that timber in hardness, strength and toughness. It weighs about the same as white ash, about 670 kg/m³ when dried and is used for similar purposes as white ash, except for striking tool handles.
- WHITE ASH The sapwood is almost white in colour and the heartwood varies from light brown to reddish-brown rather similar to European ash. but a little lighter in weight, about 670 kg/m³ when dried.