POPULUS

Other names
American whitewood, cottonwood, Canadian aspen

Distribution
North and South America, Canada

The tree
The Canadian aspen, which also occurs in the USA, is commonly 15-18m in height and 0,2-0,3m in diameter, occasionally more. The cottonwoods are generally taller, reaching 30m or more in height and 1m or more in diameter.

The timber
The wood is fairly soft and light; the average density for the different species varies between 0,40 and 0,46, seasoned. It is usually of plain appearance apart from a growth-ring figure on flat-sawn or rotary-cut material, greyish-white to light greyish-brown sometimes with a reddish tinge, with no sharp distinction between sapwood and heartwood. The grain is usually straight, the texture fine and eve. The wood is odourless and tasteless when well seasoned.

Strength
Being soft and light, poplar has a low strength rating, similar to basswood and spruce, but ranks comparatively high in toughness and resistance to shock and wears evenly under abrasion. It is unsuitable for steam bending.

Durability
All species of poplar are non-curable under damp conditions. Moreover, the heartwood is resistant to impregnation and consequently not amenable to preservative treatment.

Working qualities
The timber works fairly easily and well by both machine and hand, provided sharp, thin-edged tools are used; with dulled cutters there is a tendency for a woolly surface on planing and for the timber to crumble in end-grain cutting. It nails and screws well and presents no difficulty in finishing. The logs peel easily and the wood can be glued and painted without difficulty.

Uses
A major outlet for poplar wood is boxes and crates and wood-wool. Logs of suitable size and form are converted to veneer for matches, chip baskets for fruit and vegetables, and plywood. The poplars are an important source of wood pulp.