Quercus palustris, also called pin oak, swamp oak, or swamp Spanish oak, is a tree in the red oak section (Quercus sect. Lobatae) of the genus Quercus. Pin oak is one of the most commonly used landscaping oaks in its native range due to its ease of transplant, relatively fast growth, and pollution tolerance.
The leaves are long and broad, lobed, with five or seven lobes. Each lobe has five to seven bristle-tipped teeth. The sinuses are typically U-shaped and extremely deep cut. In fact, roughly the same amount of sinus area exists as actual leaf area. The leaf is mostly hairless, except for a very characteristic tuft of pale orange-brown down on the lower surface where each lobe vein joins the central vein. Overall autumn leaf coloration is generally bronze, though individual leaves may be red for a time, and is not considered particularly distinctive.
The acorns, borne in a shallow, thin cap, are hemispherical, long and broad, green maturing pale brown about 18 months after pollination. It develops a shallow, fibrous root system, unlike many oaks, which have a strong, deep taproot when young.
The common name "pin oak" is possibly due to the many small, slender twigs, but may also be from the historical use of the hard wood for pins in wooden building construction.
Distribution and habitat
Q. palustris is mainly distributed in the eastern and central United States from Connecticut in the northeast, west to eastern Oklahoma and Kansas, and south to Georgia. It is also native in the extreme south of Ontario, Canada.
The pin oak is also well adapted to life in England and Australia (where it has been introduced), and is quite widespread across the Australian continent, especially in the cooler southern States such as Victoria and New South Wales. It is also well adapted to life in South Africa and Argentina, especially in the Río de la Plata region.
It is naturally a wetland tree,
Ecology
Associated forest cover
Pin oak is a major species in only one forest cover type, pin oak–sweetgum, which is found on bottom lands and some upland sites throughout the central portion of the pin oak range. Pin oak and sweetgum (Liquidambar styraciflua) vary in their relative proportions in this cover type. Large areas of almost pure pin oak occur on the "pin oak flats" of the upland glacial till plains or in the bottom lands of the lower Ohio and central Mississippi River valleys. Associated species in this forest type include red maple (Acer rubrum), American elm (Ulmus americana), black tupelo (Nyssa sylvatica), swamp white oak (Quercus bicolor), willow oak (Quercus phellos), overcup oak (Quercus lyrata), bur oak (Quercus macrocarpa), green ash (Fraxinus pennsylvanica), Nuttall's oak (Quercus texana), swamp chestnut oak (Quercus michauxii), and shellbark (Carya laciniosa) and shagbark (Carya ovata) hickories.
The wood is generally marketed as red oak, but is of significantly inferior quality, being somewhat weaker, often with many small knots.