Identifying Oaks

[WDH]

I had posted an offer a while back to initiate a post on identifying the various species of oak.  I know the oaks very well, but you tend to know what you see regularly and you don't know what you don't see regularly.  That is to say a tree of a particular species might look a little different in Georgia versus Pennsylvania (I don't get to Pennsylvania much ;D).  So, I plan to start a post on the oak species, one by one for the more common ones, so that Forum members can share their experiences with that species, the special ways they have of identifying the species, and post any pics that they might have.  It would be a good way to facilitate a discussion on the various species.

So, here goes..................

[tonich]

OK!
To make things even more complicated about oaks, I will insert all the Mediterranean oaks, spread all across my country.    :D :D :D :D :D


J/K

[WDH]

Tonich,

I posted scarlet oak first, but there does not seem to be any interest.  It may be just you and me!

[tonich]

I guess, this is because oaks are REALLY complicated – a big genus, many species, variable in biology and ecology.
But it is a basic forest-forming species and worldwide spread pioneer.
So it is quite odd from my point of view…  :

[scgargoyle]

I, for one, am really interested in all things oak, since I've got a lot of 'em on my property in SC (see my response in the Scarlet thread). So far, I think I have scarlet, red, white, black, and maybe chestnut oaks. The only good look I got was in the winter, so the leaves were all mixed up, and most of the acorns were eaten. We might go back up in May, then definitely in July, so if I know what to look for, I can ID some of my trees. Thanks for helping out us newbies!

[Jeff]

I think there is a lot of interest. Its one of those things that we tend to look at and say Ah! Cool! But to ourselves. 

So, Ah. Cool!  And, also Thanks!

[Radar67]

Danny, I have been following this thread as well. I purchased the National Audobon Society's book, Field Guide for Trees, Eastern Region and it has a lot of good information in it. I didn't realize there were so many different kinds of oak.

Stew

[Jeff]

Radar67, thats a good book. I like all of those field guides.

[Radar67]

I skimmed through it last night. I have to do a little reading on the How to use section, but it looks like it will help out tremendously. I also looked at the same book on mushrooms...that's a lot of different species in there. 

Stew

[DWM II]

This is cool, I am ignorant in the text book sense when it comes to oak I.D. Do they all fall into the "red" or "white" catagory? I can pick out a true white oak but then I also call saw tooth trees white oaks as well. Is a water oak a red oak? I could ask 100 questions so I'll just stay tuned to the posts, thanks for taking the time to share your knowledge.

[WDH]

Yes, DWM II,

All oaks fit into two categories

1).  The White Oak Group

or

2).  The Red Oak Group

Water oak falls into the red oak group.  The red oak group has spines on the leaves at the leaf tip on on the end of the lobes.  The white oaks don't have spines.  Also, red oak acorns take 2 years to mature while white oak acorns mature in one year.  The good thing is that the leaves and bark of the two groups are distinctly different.  More about that later.

[Lanier_Lurker]

I would have expected water oak to be in the white oak group given its leaf shape.

[Texas Ranger]

To complicate things, oaks have variations in leaf shapes, not only within a species, but within a single crown.  They respond to light conditions and can be really difficult in a full crown cover stand.  In the old days, I would shoot a limb out of the top to try and get a text book leaf.  Sometimes works.

[wesdor]

So now I am a bit confused (nothing new for me).  Is a Swamp White Oak a water oak or a white oak?  I planted about 100 of them last year thinking they were White Oak.

I suppose it will be more than a couple of years before they make good saw lumber, so my question isn't too time critical.

[Ron Wenrich]

Swamp white oak is a white oak.  In a wild setting, its more at home in wetlands than it is on dry areas.  I've never seen it in dry areas, come to think of it.  Quality of lumber from swamp oaks is usually pretty dismal, due to the overly amount of limbs that seem to hang on forever.

[Lanier_Lurker]

The overall shape of water oak leaves tends to be pretty consistent - although the size appears to vary greatly.

But, I have never seen any water oak leaves with spines or bristles.  Thus, my confusion about WDH classifying them as a member of the red oak group.

[Texas Ranger]

Water oaks around here can have leaves that look like willow oak, water oak, and post oak, all on the same tree.  Try to get a picture, they are not rare.

[DWM II]

Post oak-is that also pin oak? Also does the water oak have a similar leaf as the pin oak only with the points on the ends of the lobe? I have many pin oaks and then there's the one with a similar leaf I described.

[WDH]

Water oak does have spines on the leaves early on in the season.  Also there are 3 or four shapes that water oak leaves display like Texas Ranger pointed out.  Some are unlobed, some are three lobed at the tip, some are spatula shaped (leaf widest at the tip, and some are actually lobed with sinuses (indentati.ons toward the mid-rib).  Again, as TR pointed out, sometimes on the same tree.  So you have to look at all the leaves from top of the crown to the bottom.  Water oak will be fun when we get to that post (stay tuned) because is a little like a master of disguises ;).  We will do a post on it by itself so as to reveal its many disguises :D

Now the question of pin oak as DWM II brings up.  In the mid-South, people refer to a "pin oak",  from local custom that is usually an oak with a long lance shaped leaf that is very regularly shaped, or a leaf that is longer than broad, but otherwise unlobed.  This is, most times, truely what is defined as a willow oak (Quercus phellos) or laurel oak (Quercus laurifolia) depending on the length and width of the leaf.  A true pin oak is a more northern tree that has a leaf very deeply lobed with many bristle tips on the lobes very much like the shade leaf scalet oaks.  I know this may seem confusing, but true pin oak (Quercus palustris) is a species in its own right and does not occur in the deep South and not on the bottomlands.  So "pin oak" in the deep south is not really a true pin oak but a local name for what is actually willow oak and laurel oak.  Clear as mud ???.

[Lanier_Lurker]

Yep, I learnt about the whole pin oak/willow oak thing many years ago.

There are many willow oaks and true pin oaks planted as ornamentals in the downtown Atlanta areas of Woodruff Park and Underground.

WDH, I never would have thought water oak was in the red oak group.  You have taught me something.

[scgargoyle]

What about live oak? Or are they in another group of their own? They grow their (numerous!) acorns in one season, and they practically sprout on the way to the ground.

[WDH]

Live oak is considered to be in the white oak group.  Live oak is a little bit of an anomaly.  It can sometimes be a cross-dresser.  But the accepted and historical botanical/dendrological classification of live oak is a member of the white oak group.

[DanG]

I've always felt that there should be 3 Oak groups...Red, White, and Live.  I didn't get to vote, though.

[Dodgy Loner]

DanG, your opinion reflects that of many modern taxonomists.  The reason live oak has been considered to be a white oak for so many years is primarily based on two things: the acorns mature in 1 year (red oak acorns take 2 years to mature), and live oaks only hybridize with members of the white oak group (an example is Compton oak, which is a hybrid between an overcup oak (Quercus lyrata and live oak Quercus virginiana).

However, modern DNA research has shown that live oaks are about as genetically different from white oaks as red oaks are.  Anyone who has seen live oak wood knows that it is very different from both red oak and white oak.  It's much harder and heavier, it's pore arrangement is semi-ring-porous, rather than ring porous, and the pores themselves are much smaller.  For those reasons, I have to agree with DanG and place live oak in a separate group.

[WDH]

Sometimes nature does not like neat little pigeon holes .  We like convenient distinct groups and boxes and classifications, but sometimes we have to stretch things to fit ???.