Pin Oak
Quercus palustris
Summary 5
Quercus palustris, the pin oak or swamp Spanish oak, is an oak in the red oak section Quercus sect. Lobatae. 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. Its distinctive shape is considered unique among hardwoods.
Quercus palustris is a medium-sized deciduous tree growing to 60 – 72 feet tall, with a trunk up to 3 1⁄2 ft in diameter. It has an 25 – 45 ft spread. A 10-year-old tree grown in full sun will be about 25 ft tall. Young trees have a straight, columnar trunk with smooth bark and a pyramidal canopy. By the time the tree is 40 years old, it develops more rough bark with a loose, spreading canopy, considered one of the most distinctive features of the pin oak: the upper branches point upwards, the middle branches are at right angles to the trunk, and the lower branches droop downwards.
The leaves are 2 – 6 inches long and 2 – 5 in 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. 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. The acorns, borne in a shallow, thin cap, are hemispherical, 10–16 millimetres 3/8 – 5/8 in long and 1/3 - 5/8 in broad. Unless processed using traditional methods, the acorn is unpalatable because the kernel is very bitter.
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 trees, a natural phenomenon referred to as marcescence.
Due to similarity in leaf shape, the pin oak is often confused with scarlet oak and black oak, and occasionally, red oak. However, it can be distinguished by its distinctive dead branches on the lower trunk ("pins"), and its uniquely shaped crown. The sinuses on pin oak leaves are also deeply cut, often covering just as much area as the leaf itself.
Sources and Credits
- (c) Kelly Krechmer, some rights reserved (CC BY-NC), uploaded by Kelly Krechmer
- (c) Jodi Bucknam, some rights reserved (CC BY-NC), uploaded by Jodi Bucknam
- (c) chillbobagginz, some rights reserved (CC BY-NC)
- (c) Bruce Kirchoff, some rights reserved (CC BY), https://www.flickr.com/photos/brucekirchoff/20133734406/
- Adapted by Tom Pollard from a work by (c) Wikipedia, some rights reserved (CC BY-SA), https://en.wikipedia.org/wiki/Quercus_palustris
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