Pin oak

Appearance

It is a medium-sized deciduous tree growing to 18–22 metres tall, with a trunk up to 1 metre diameter. It has an 8–14-metre spread. A 10-year-old tree will be about 8 metres tall. The crown is broad conic when young, with numerous small branches radiating out from a central leader. When older, some upper branches become quite large and the central leader is lost, while the lower branches gradually droop downwards.

The leaves are 5–16 centimetres long and 5–12 centimetres broad, lobed, with five or seven lobes. Each lobe has 5-7 bristle-tipped teeth. The sinuses are typically u-shaped and extremely deep cut. In fact, there is approximately the same amount of sinus area 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. The acorns, borne in a shallow, thin cap, are hemispherical, 10–16 millimetres long and 9–15 millimetres broad, green maturing pale brown about 18 months after pollination. The acorn is unpalatable because the kernel is very bitter.

A fast-growing pioneer or riparian species, Pin Oak is relatively short-lived, with a maximum lifespan of 120 years against many oaks which can live several centuries. It is naturally a wetland tree, and develops a shallow, fibrous root system, unlike many oaks, which have a strong, deep taproot when young. It is confined to acidic soils, and does not tolerate limestone or sandy Florida soil, and grows at low altitudes from sea level up to 350 m . The Latin specific epithet ''palustris'' means "of swamps".

A characteristic shared by a few other oak species, and also some beeches and hornbeams, is the retention of leaves through the winter on juvenile tissue. Young trees under 6 metres will often be covered with leaves year-round, though the leaves die in the fall, remaining attached to the shoots until the new leaves appear in the spring. As with many other oak species, dead pin oak branches will stay on the tree for many years.

The pin oak can give off a strange skunk-like odor. The acorns are small with a thin, shallow cap. The pin oak is in the red oak subgenus: pointed lobes. The sinuses are very deeply cut and u-shaped. The amount of sinus area is approximately equivalent to the amount of actual leaf area. The upper branches point upwards, the middle branches are perpendicular to trunk, and the lower branches angle down.

Pin oak grows primarily on level or nearly level, poorly drained alluvial floodplain and river bottom soils with high clay content. Pin oak is usually found on sites that flood intermittently during the dormant season but do not ordinarily flood during the growing season. It does not grow on the lowest, most poorly drained sites that may be covered with standing water through much of the growing season. However, it does grow extensively on poorly drained upland "pin oak flats" on the glacial till plains of southwestern Ohio, southern Illinois and Indiana, and northern Missouri. The level topography and presence of a claypan in the soil of these areas cause these sites to be excessively wet in winter and spring.

Distribution

It is native to North America, mainly in the eastern United States from Connecticut west to eastern Kansas, and south to Georgia, across to eastern Oklahoma; it is also native in the extreme south of Ontario, Canada. The pin oak is also well adapted to life in Australia and is quite widespread across the Australian continent especially in the cooler southern States such as Victoria and New South Wales. Is also well adapted to life in Argentina, especially in the Río de la Plata region.

Uses

Pin Oak is one of the few ''Quercus'' species extensively used as a landscaping tree due to its ease of transplant and faster growth than most oaks. However, as it is naturally adapted to wet, acidic soils, it may develop a condition known as iron chlorosis on less suitable locations, causing the tree to shed leaves during the growing season and rot from the top down. Mature Pin Oaks are often too big to treat and this nutrient deficiency on alkaline soil may eventually kill them. The drooping lower branches can also be a problem, interfering with access for traffic and pedestrians. It is also cultivated in parks and large gardens in the United Kingdom, and has gained the Royal Horticultural Society's Award of Garden Merit.

The wood is generally marketed as red oak, but is of significantly inferior quality, being somewhat weaker, often with many small knots.1. The wood is hard and heavy and is used in general construction and for firewood.

The bark was used by some Native American tribes to make a drink for treatment of intestinal pain.

The 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 .

The pin oak is the only known foodplant of ''Bucculatrix domicola'' caterpillars.