Oak Tree

An Oak

One of my goals for this year is to become acquainted with the various trees of Illinois. Often the species of tree is significant when it comes to identifying other organisms, such as insects or fungi. Knowing that a particular mushroom usually grows in the vicinity of a certain tree, for example, can help in locating said mushroom. After all, trees are usually much bigger than mushrooms and easier to spot from a far.  On my trip to the Isle a La Cache Forest Preserve, I took a photo of the tree opposite. I recognized it as an oak, because you know, it has leaves that look like oak leaves. What species, however, I had no clue.  

Oak leaves.

Of the roughly 600 species of oak, there about about 52 that are native to the United States, and 20 to Illinois. The latter group are: bur oak, chestnut oak, chinkapin oak, overcup oak, post oak, swamp chestnut oak, swamp white oak, white oak, black oak, blackjack oak, cherrybark oak, northern pin oak, northern red oak, nuttall oak, pin oak, scarlet oak, shingle oak, shumard oak, southern red oak, and willow oak. 

Tree Bark. Woof, woof.

So, if I fake expertise and take a wild guess, then I have roughly a 5% chance of getting it right. Sadly, that  means I have a 95% chance a being corrected when confronted with someone who actually knows what he is talking about. I don't like those odds.

Fortunately, we can improve things by knowing a few facts about each each species. Hill's oak (Quercus ellipsoida), for example, is usually only found in the northern counties, whereas Spanish oak (Quercus falcata), Rock Chestnut Oak (Quercus montana), and Southern Red Oak (Quercus falcata) in the south. Or better yet, you just memorized the characteristics  specific to each tree. Imagine that!

My first assumption upon seeing the deep grooves of the bark was that this was a Bur oak (Quercus macrocarpa), yet the leaves do not have the deep sinuses typical of the tree. Another oak that has deep fissures is the swamp white oak (Quercus bicolor), which fits nicely into fact that the tree is situated in a flood plane. The colour of bark is grayish, the leaves wider at tip than at the base, and the lobes are not pointed. All these facts suggest that this is indeed the swamp white oak.