January 18th, 2013 by
Great Falls Park in January 2013

Great Falls Park in January 2013. Credit: mebrett/Flickr

This last weekend, I went on a wonderful hike around Great Falls Park. As we started the hike, I was quickly reminded of the Winter Tree ID class that I took several years ago, where we went on a field trip to that exact same location at this time of year to identify the trees. As I looked around, I realized that this was perfect timing to continue testing out my knowledge, especially without many leaves around to help me out!

While leaves can make tree identification much easier, it is always a fun and exciting challenge to correctly identify trees in the winter — and it is often not really all that hard. So, for the next hike that you take or the next stroll around your urban forest, you can use these helpful tips to make the most of it and figure out what type of trees you are walking by. Note: These tips relate to deciduous trees, and the examples are often from the East Coast.

Branching out!
Observing the leaf and twig arrangement can tell you a lot about the kind of tree you are seeing. There are three main structures that you will look for:

  1. Trees with alternate leaf attachments have one unique leaf at each leaf node and usually alternate their direction along the stem.
  2. Red maple

    Red maple. Credit: Becca MacDonald, Sault College, Bugwood.org

    Trees with opposite leaf attachments have a pair of leaves at each node. The joy of opposite leaves is that only a few common tree families have these, and there is an easy acronym to remember: MADCap Horse.
    * Maples
    * Ash
    * Dogwood
    * Honeysuckle/Viburnum (aka. Caprifoliaceae)
    * Horse chestnut

  3. Trees with whorled leaf attachment often have three or more leaves attached at each node on the stem.

Be a Twig Detective!
Twigs can often be identified by observing the following:

  1. Buds – Buds are a useful ID because they are set in different ways and look different when you look up close, specifically at the shape, size and scales (which protect the buds).
  2. Bark – Look at the color and pattern (more to come on that).
  3. Leaf scars – These are below the buds and are left when the leaf falls off in autumn. The scar will look different for each kind of tree. Look at the shape, pattern and arrangement of scars.
  4. Pith – The soft center section of the twig is important for storage and transport of nutrients. Look at the color and chambers of the pith.

To help in this, find a good twig key, such as this one, to help you go step-by-step in determining where the twig came from.

Eastern redbud fruit

Eastern redbud fruit. Credit: Paul Wray, Iowa State University, Bugwood.org

Find the Fruits!
Often in the winter, you will see some conspicuous, persistent fruits on the trees or evidence of the fruits below the trees. In most good tree identification books, you will be able to search out different types of fruits. A few common fruit types that you may find in the winter include:

  1. Berry – a fleshy fruit (ex. paw paw)
  2. Nut – a hard, bony fruit with one seed (ex. acorns from an oak)
  3. Samara – one-seeded (ex. the winged fruit of maples)
  4. Achene – a small dry fruit with one seed inside (ex. sycamore)
  5. Legume – a fruit with several seeds that splits open at maturity (ex. redbud)

Learn the Bark!
Tree bark is an especially useful tool for tree ID in the winter. And, of course, there are various ways to describe what a bark might look like. Here are a few descriptions you might use when comparing tree bark:

  1. Smooth, like beech tree
  2. Shaggy, like shagbark hickory
  3. Blocky, like persimmon
  4. Ropey, like black walnut
  5. Warty, like hackberry
  6. Diamond, like green ash
  7. Peeling, like sycamore

Check out a recent article in the American Forest magazine that goes into much more detail about the importance of bark and the varieties that exist. Don’t have a copy of the magazine? Check back next week when we post the article online.

Happy winter tree ID’ing! Hope you are able to ID all sorts of trees in your winter urban wonderland!