What Is A Tanbark Oak?
TANBAK OAK PLANT INFO: WHAT IS A TANBAK OAK?
Tanbark oak (Tanbarksia latifolia) is a hardwood tree native to North America. It grows up to 30 feet tall and 15 feet wide with a trunk diameter of 1 foot or less. Its leaves are oval shaped, dark green, and elliptical in shape. They have five leaflets per leaf and are arranged in two rows along each side of the stem. The wood of the tree is light brown to black in color.
The name “tan” refers to its reddish brown color, while “oak” comes from the Spanish word for oak which means “maguey.”
It was named after John William Tansey, a botanist who lived in New Jersey during the late 1700’s.
In 1790, the first specimen of this species was collected in Virginia. Since then it has spread throughout much of the eastern United States and into Canada.
Its common names include tan oak, red maple, chestnut oak, chestnut chestnut, black walnut, American elm and American ash. These are all appropriate since they grow mostly in forests where these trees occur naturally.
It has been introduced to the United Kingdom and is occasionally cultivated as a street tree in urban areas.
TANBAK OAK PLANT INFO: GEOGRAPHIC RANGE
TANBAK OAK PLANT INFO: ECOLOGY & HABITAT
In North America, tanbark oak is found throughout the eastern half of United States and parts of southern Canada. It is also found in northern Mexico.
It grows at the edges of deciduous forests, especially in upland areas such as plateaus and mountains. It is commonly found in dry, rocky, and well-drained soils.
Its growth is favoured by alkaline and calcareous soil types. It also prefers light and dry soil conditions, such as those found on chalk ledges.
TANBAK OAK PLANT INFO: DESCRIPTION
TANBAK OAK PLANT INFO: POPULARITY
The tanbark oak is a fast growing tree that reportedly reaches maturity within 10 to 15 years. It has a straight trunk with a greyish bark.
The upper branches are lined with sharp thorns which sprout from the sides of the twigs.
The leaves are dark green and oval shaped, having 5 to 7 pointed lobes. They turn yellow in autumn before falling off the tree.
The tanbark oak is a dioecious species meaning that there are separate male and female trees. The male flowers are small and grow in clusters, appearing from May to July.
The female flowers are inconspicuous, growing in bundles of three at the base of the leaves. They appear from April to August.
The fruits are acorns which ripen in September. They have scruffy brown cups that enclose the acorn which fall from the tree in autumn.
TANBAK OAK PLANT INFO: USES
TANBAK OAK PLANT INFO: MOSAIC
The tanbark oak is one of the most important hardwoods in North America. It has many uses due to its high tannin content which makes the wood resistant to insects and decay so it can be used outdoors without treatment.
The tannins are also used for tanning leather with its bark removed. Tannin is also used in the making of inks, paints, and dyes.
The wood is very hard and dense, weighing around 750 kilograms per cubic metre. It has a high energy content when burnt, but is not easy to light.
It splits well and takes nails and screws well.
The bark contains up to 30% tannin which is extracted for use in leather tanning. The bark can be stripped in large sheets from live trees.
It can also be harvested from the base of dead trees.
Trees are often over-tapped, and when this happens the tannin levels become diluted in older trees so younger trees need to be used when a new “tannery” is set up.
The bark is removed in strips and the underbark is removed. The bark is then soaked in water and mixed with wood ash or slaked lime to loosen the tannin, which can then be drained off and put into settling tanks.
It is then put through a process of mixing it with water and sediment which causes heavier impurities such as wood fibre and minerals to sink and lighter tannins soluble in water to float. The final product is a brown water which contains about 30% tannin.
There are still many uses for tanbark oak today despite the fact that most leather now comes from cow hides rather than wild animal hides. Tanning leather with tannin increases its resistance to water and prevents it from decaying.
Tannin can also be used in the removal of iron gall ink, dye, and paint stains from paper.
TANBAK OAK PLANT INFO: CONCLUSION
The tanbark oak is a very useful tree that can be used in many ways. Although it is a relatively unknown species, it should be more widely used as a resource.
The tanbark oak is also a relatively common tree, at least compared to some trees. This means that it should be fairly easy to gather enough bark to make use of all its potential benefits.
The tanbark oak is a very versatile and worthy tree that more people should become familiar with. It’s always useful to have access to many different resources after all.
Tanbark oak trees can grow in virtually any soil and can even survive fires. They can even be grown from acorns.
It is easy to see that this tree would have been of great importance to the Native Americans who first inhabited California. It is a shame that it isn’t more well-known today.
The tanbark oak can grow fairly large too, with some specimens reaching 25 feet tall and 50 feet wide. It can live for hundreds of years too, so a tanbark oak tree could be a resource for many decades, possibly even centuries.
There is one downside though. Tanbark oak trees only grow to a large size in California’s Central Valley.
If you live anywhere else, such as most of the rest of North America, the tanbark oak is only going to reach a medium size. It’s still useful, but not as much as it could be.
The tanbark oak’s main “rivals” are the black oak and the white oak. The black oak grows much larger than the tanbark oak and can be used in many of the same ways.
The white oak doesn’t grow as large, but it can be used even in its medium size for tanning leather. The white oak also has more uses than the tanbark oak, which is mainly just used for tanning.
However, the tanbark oaks are very easy to recognize and make a good substitute if you don’t live where they naturally grow or if you need more tanbark oak bark than you can collect.
MORE INFO ON TANBAK OAKS:
Tanbark Oak (California)