Wood of the Month:
Black Poplar Makes for Popular Mappa Burl

By Jo-Ann Kaiser


FAMILY NAME
Populus candensis, Populus nigra and Populus serotina of the Family Salicaceae. Other species include Populus robusta and Populus tremula.

COMMON NAMES
Italian poplar, European black poplar, black Italian poplar.

HEIGHT/WEIGHT
Average height of black poplar is 100 to 115 feet with diameters of 3 to 4 feet. Average weight is 28 pounds per cubic foot. Specific gravity is 0.45.

PROPERTIES
The wood is usually straight-grained and woolly with a fine, even texture. It dries rapidly and well with little degrade. Black poplar has low bending strength, very low stiffness and shock resistance. It has medium crushing strength and is rated very poorly for steam bending. The wood will work well with hand and power tools but cutting surfaces must be kept sharp. Experts recommend thin-edged cutters. It will hold screws and nails well, but staining can be difficult.

A European species, black poplar has gained popularity in the United States as a veneer, available in both plain or fancy grain patterns. One of the more recognizable patterns from Populus nigra is mappa burl, a highly figured burl.

The Fine Hardwoods Selectorama, written by Larry Frye, executive director of the Fine Hardwoods/American Walnut Assn., describes mappa as a burl from Central Europe that is white to brownish-green in color. Its pattern is "burley with little reddish spots, usually quite sound."

Mappa burl, like the other figured veneer cut from Italian poplar, is used for furniture and architectural uses. Al Matulevich of the David R. Webb Co., in Edinburgh, IN, described mappa burl as "highly figured but with good dimension compared to other burls. The 2-foot by 4-foot cuts are typical, but you can also get leaves as long as 5 feet by 9 feet when rotary cut.

"Mappa burl is not as intense a figure as some other burls. The figure is larger in scale than other burls. It has almost a muscle-like figure," said Matulevich.

Scott Thompson, custom account manager for Carl F. Booth & Co. of New Albany, IN, said his company has used mappa burl in manufacturing veneers for the aviation industry. "Mappa burl can be difficult to work with because it has a lot of holes that need to be filled. That can make the job labor intensive."

Matulevich added that Italian black poplar is not to be confused with ebonized poplar. "That is American poplar, which is sent to Milan, Italy, where it is dyed or 'ebonized' and used as a substitute for African blackwood. It is sold under the trade name tulibier," Matulevich said.

Variety of Uses
In addition to its popularity in the furniture and architectural industries, poplar is used for match splints and wood wool, also known as excelsior, and for chip baskets. Italian black poplar is tough and will not splinter unlike some softwoods, but it can be "woolly" and is therefore used in its roughest form for the bottoms of trucks and wagons and for furniture framing and interior joinery.

Logs can be rotary cut and used to make plywood and corestock. Selected logs of European poplar are also sliced into veneer. This poplar has more color than the average wood, which is creamy white or light gray. Lustrous, it has streaks of pink and orange and is used for furniture and cabinetry instead of the more utilitarian uses such as toys, boxes, crates and flooring.

Poplar's heartwood is creamy-white to grey in color but it can also be a pale brown. The heartwood and sapwood are not clearly defined as in some woods and poplar's sapwood is a large part of the tree. The sapwood is permeable and can be treated with preservatives. The heartwood of poplar can sometimes be slightly resistant to preservative treatment.

Poplar will dry rapidly and well but the wood may have local pockets of moisture that cause drying problems. Knots in the wood sometimes split.

Part of the Willow Family
Italian black poplar is part of the willow family. As Hugh Johnson explains in his book, Encyclopedia of Trees, "The four branches of the family are the black, white, trembling and balsam poplars. The black (poplars) are the biggest branch, containing all the poplars which aren't white under the leaves, don't smell of balsam in bud (or if the twigs are bruised), and don't tremble (as the aspens do)."

Johnson adds that poplars, like willows, are either male or female. Both poplars and willows dominate the scenery in Europe where the fast growing trees are favorites for landscaping. "The interbreeding of the four different groups of poplars has given us some of our most useful and fastest [growing] trees," Johnson writes. Famous hybrid black poplars include canadensis, serotina, marilandica, regenerata, Italica and Plantierensis.

American poplars include cottonwood, balsam poplar, bigtooth aspen and quaking aspen. These trees are valuable for commercial uses as timber. Other poplar species commercially cut in Europe include Populus canadensis, which produces Italian black poplar; Populus robusta known as robust; and Populas tremula, which goes by a variety of names according to the country of origin, including Finnish aspen, French aspen, or European aspen.

                                                                                                                                                                                           

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