Alder
Description
Several species of deciduous trees from the genus Alnus. Alders are in the same family as birch trees. The wood from alder trees has a smooth, fine, straight grain; it is tough and resilient. The red alder, A. rubra or A. oregana, found along the west coast of the US and Canada, has reddish-brown wood that is prized for cabinetry, furniture, and imitation mahogany. Wood from other alder trees is used for plywood, shoe heels, bobbins, cogs, and other small turned items. The bark from the black alder, A. glutinosa, was used in 15th century Europe to produce a black dye for cloth. Native Americans and Eskimos also used red alder bark to make a brown dye for basket materials and reindeer skins. Alder bark and fruit contains up to 16% tannins and they have occasionally been used for tanning leather. However, alder produces a brittle leather unless used in conjunction with other tannins.
Synonyms and Related Terms
red alder (Alnus rubra); Oregon alder (Alnus oregana); black alder (Alnus glutinosa); yasha (Jap.); el-slægten (Dan.); Erlen (Deut.); aliso (Esp.); aulne (Fr.); ontano (It.); els (Ned.); olsza, olcha (Pol.): amieiro (Port.)
Other Properties
Tree height = 30-35 m Bark = smooth, light gray, often covered with white lichens Flowers = catkins, male and female on same tree (late spring) Fruit = semi-woody cone
Specific gravity = 0.53
| Density | 28-33 ppcf |
|---|
Paper fiber type: hardwood, diffuse porous. Using transmitted light microscopy, pulp is identified by long vessels (up to 1mm) with a tapered point and alternate, small pitting. Perforations are scalariform with 12-25 bars, some branched. Vascular trachieds may be present. Appearance with Graff "C" stain: dark blue, but varies with bleaching. Average dimensions of fibers: length, 1.2mm. 28μm wide. Common pulping method: kraft.
Additional Information
° Schoch, W., Heller, I., Schweingruber, F.H., Kienast, F., 2004: Wood anatomy of central European Species: Black Alder, Alnus glutinosa Gaertn.
Additional Images
Red alder (Alnus rubrum)
Red alder (Alnus rubrum)
Red alder (Alnus rubrum)
Black alder paper pulp
Black alder paper pulp
Sources Checked for Data in Record
- G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971
- Matt Roberts, Don Etherington, Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology, U.S. Government Printing Office, Washington DC, 1982
- Dictionary of Building Preservation, Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996
- Palmy Weigle, Ancient Dyes for Modern Weavers, Watson-Guptill Publications, New York, 1974
- F. H. Titmuss, Commercial Timbers of the World, The Technical Press Ltd., London, 1965
- Website address 1 Comment: Virginia Tech Dencrology website at www.fw.vt.edu/dendro/dendrology/main.htm (accessed Oct. 3, 2005)
- Wikipedia, the free encyclopedia, at http://www.wikipedia.com Comment: http://en.wikipedia.org/wiki/Alder (Accessed Oct. 3, 2005)
- CRC Handbook of Chemistry and Physics, Robert Weast (ed.), CRC Press, Boca Raton, Florida, v. 61, 1980 Comment: density=26-42 ppcf (0.42-0.68 g/cm3)
- Marja-Sisko Ilvessalo-Pfäffli. Fiber Atlas: Identification of Papermaking Fibers (Springer Series in Wood Science). Springer, 1995.
- Walter Rantanen. "Fiber ID Course." Integrated Paper Services. June 2013. Lecture.