Poplar

Other commercial names Black Poplar, White Poplar and European Aspen
Botanical name Populus nigra L.; Populus alba L. | Populus tremula L.

Historical and cultural information
In order to escape from Hades, god of the Underworld, the nymph Leuke turned herself into a white poplar. Now this tree is found on the threshold of the Underworld, the fountain of Mnemosine. Once upon a time, during the hardest winters, raw poplar bark was chewed for nourishment. This tough, light wood was ideal for making clogs (Dutch, German or Italian). For these same reasons, during the XIX century, it was laid as the carriageway wearing course of suspended bridges.

General information
Among all national species, poplar grows the quickest. Other than the three national species – white, black poplar and aspen- there are numerous cultivated varieties. Grey poplar, for example, is a hybrid of white poplar and aspen; cypress poplar is a particular type of black poplar which can be reproduced only by vegetative means. The majority of poplar wood is cultivated. At 30 – 50 years the trees reach dimensions that make them suitable for use. Maximum age for aspen is 100 years, while both black and white poplars can reach 400 years.

Characteristics
The edges of the annual rings, generally wide, are marked by a band of dense and thin late wood. Vessel number and dimensions vary little within the ring, which makes spring and late wood difficult to distinguish. The wood is very smooth with a loose grain. On longitudinal sections the pores look like thin grooves.

Properties
Aspen timber (dry density 450 kg/m3) is the heaviest among poplar trees: these are the national species with lighter wood (dry density 410 kg/m3). The wood is very tender (Brinell hardness 10 – 11 N/mm2) but tough and can be dried from well to moderately well. Processing is good although because of the frequent presence of reaction wood, planing may give rise to wavy surfaces. It can be varnished and lacquered with success but it is difficult to sand. This wood is highly vulnerable to fungi and insects (durability class 5). Its impregnability is poor, but good in the sapwood.

Use
Poplar is typically used for manufacturing matches and packaging (fruit crates, baskets etc). The logs are made into rotary cut veneers which are subsequently cut into various sizes. Part of the poplar wood production is used for making plywood, however the majority serves as timber for the cellulose and chipboard production industry. Fiddleback figured logs, in particular the black poplar ones, are transformed into quality veneers.