Pin Oak

Basic Information
Tree ID: 
Genus and species: 
Hidden among the foliage near Marsh Botanical Gardens, this tree is hard to come across. In order to access this tree, one must have climbed through slushy mud or a sea of beautiful angiosperms, depending on the season. This tree is fairly large, standing at nearly twenty four meters tall. Aside from its height, this tree's most distinctive features include its unique branching and rough bark.
Megan Sardis and Angela Gong
Collected Data
Tree shape: 
loose, spreading canopy; rough bark
Date of tree entry: 
23.74 m
Diameter at breast height: 
1.94 m

The bark of a younger pin oak tree would appear more smooth. This makes it hard for insects and ivy to gain hold. However, we know that this particular pin oak is older than approximately forty years old, because the bark appears rough. The color is a dark grey-brown. The rough bark serves the purpose of protecting the tree's essential living systems from temperature fluctuations and of conserving water. As the tree grows, the bark flakes off and grows rougher, exposing patches of the underparts of the tree.
Twigs & branches
The name "pin oak" is possibly due to the many slender, small twigs that this historical tree has. They are reddish brown, and very thin. They are hairless, with terminal buds clustered at the ends of the twigs. These buds are young, undeveloped leaves, which present themselves in the spring.
The leaves are broad and have about five or seven lobes. Each lobe has bristle tips and is mostly hairless. The autumn leaf coloration is generally bronze and the individual leaves can turn red over time. This is not a particularly distinctive feature for a tree living in this area. However, the canopy of this tree is considered very distinctive. The upper branches point upwards with the middle branches at right angles and the lower branches pointing downwards. This creates a loose, spreading canopy among older pin oak trees.
Reproductive Structures
Acorns are the fruit of this type of tree. They begin as small clusters of cells at the tip of a pin oak branch. The Pin Oak is monoecious, meaning that the plant is a hermaphrodite and has both male and female flowers. In the spring, these cells swell to create a fuzzy tiny knob on the end of the twigs, which catch pollen (male gametophytes) from the wind for fertilization. This is the ovary. Once fertilized, the ovary walls become the acorn. Pin Oaks prefer not to self breed, much like other monoecious plants. This is because self-fertilization decreases genetic diversity in a population. Pollen and female ovaries appear on the tree at different times for this reason. Male flowers are called catkins, and they release thousands of tiny pollination particles into the air for reproduction.
The type of fruit that a Pin Oak creates is a nut, or an acorn. The acorn is made of a thin cupule with a saucer-shaped cap on top. Acorns generally contain one seed each. It can take anywhere from 8 to 13 months for this zygote to develop to maturity and be ready to fall off the tree. The quantity and amount of time to maturity depend largely on the specific region in which the Pin Oak is found. This is because of varying climates, which can affect reproduction.
  • Summer
  • Fall
  • Winter
  • Spring
Natural range of distribution: 
The Pin Oak is native to Ontario, Canada. The tree can mainly be found in the central and eastern parts of the United States. It spreads from Kansas east to Connecticut, and south to Georgia. It can also be found spreading from west to east (Oklahoma to Kansas). The tree has been introduced to Australia where it has adapted well and spread across the continent. It gravitates towards the cooler souther States like New South Wales and Victoria. The tree has also adapted to life in South Africa and Argentina. The Pin Oak grows on primarily poorly drained, level, alluvial flood plains and river bottom soils with a high clay content. Areas that flood intermittently but are not poorly drained are generally the preferred areas for the Pin Oak. However, these trees can be found on "pin oak flats" in Ohio, Indiana, Illinois, and Missouri. These flats are poorly drained glacial til plains with clay filled soil.
Origin, history, and uses: 

The Pin Oak was first scientifically classified around the 1770s. Historically, Native American tribes would take advantage of Pin Oak bark by boiling it and creating intestinal medicine. The hard wood of a Pin Oak tree could be used for wooden contruction. The heavy and strong wood could be used for wood, wood pulp and railroad ties. Today, Pin Oaks are generally used for landscaping. They can be seen on the sides of highways and roads. 

The male gametophyte, or the catkin, reaches maturity at a different time of the year than the female ovaries. The pollen capsules released by the catkins travel through the air to reach the ovaries of neighboring Pin Oaks or of twigs on the same tree, as Pin Oaks are monoecious (aka hermaphroditic). Then, pollen tube formation begins and there is double fertilization. The Zygote does not reach maturity as an acorn until a few months later, when it falls off of the tree. It takes another twelve months before the fallen acorn has reached its full ripeness, making it vulnerable to rodents and small animals who want to snack on it. The Pin Oak follows a similar annual cycle to many other north american trees. It begins shedding its leaves in October in preparation for a long winter. This allows the tree to conserve resources and energy. An interesting fact about Pin Oaks is that they are intolerant to shade. This means sometimes they are outcompeted by other trees like the elm or sweetgum.
1. “Pin Oak”, Bellarmine University.
2. “Quercus Palustris,” Wikipedia. 
3. “Pin Oak”,  Arbor Day Foundation. 
4. Natural Resources Conservation Service, United States Department of Agriculture, “Plant Fact Sheet: Pin Oak Quercus palustris (Plant Symbol = QUPA2)”, 5 February 2005. 
5. Edward F. Gilman, Dennis G. Watson, “Quercus palustris​ Pin Oak Fact Sheet (ST-555)”, Department of Agriculture, Forest Service, October 1994. 
Media and Arts


Quercus palustris

We first met in the winter

Your branches were bare


In spring peeks of green

From your spindly rough brown limbs

Blooms will soon emerge


The bright summer beams

Radiant on your figure

Cast you in shadow


Crisp fall foliage

Acorns and squirrels galore

Red and brown leaves drop

Image icon Artistic Project2.47 MB