Red Oak or Black Oak?

Does anyone know of a clear, defining characteristic between the Southern Red Oak and the Black Oak.

Take a look through the USDA Field Guide to the Native Oaks of eastern North America (warning: huge 8.3 megabyte pdf file!):
http://www.evergreen.edu/library/govdocs/pdf/forestservice/guides/native-oaks2003.pdf

Resin

Thanks Resin, I think we are going to see if we can't find a photographer with a high powered telephoto lens so we can try to get a clear picture of the leaves. They are just too high up to see well.

Or wait for a gale, or a squirrel, to break a twig off! You'll almost certainly need that to see details of pubescence.

Resin

LOL, we have actually considered asking someone to shoot a branch off. I searched the ground for old acorns but the squirrels got every one it seems.

Typically Black Oak will have darker colored checkered bark with deeper cracks and fissures than Southern Red Oak. Also, the end buds on Black Oak will be very strongly 5 sided when looked at from the top(the pointy end) down and will be much larger(twice as large) than the end buds of Southern Red Oak. The end buds on Black Oak are a light reddish tan color, while those of Southern Red Oak are a dark reddish brown. Also, Black Oak will typically have larger leaves with more lobes and teeth than the leaves of Southern Red Oak. Southern Red Oak often has leaves which resemble a Turkey foot, with one long terminal lobe and 2 much shorter lobes on each side near the base of the leaf. Also, Southern Red Oak is unusual(when compared to most others in the Red Oak section) in that it has a "U" shaped or rounded leaf base, while Black Oak will have a broad wedge shaped leaf base with no rounding. You can also do the bark test by chipping off a small piece of bark and seeing what color the inner bark is. It will be a distinct yellow or bright orange-yellow with Black Oak and with Southern Red Oak it will at best be a very washed out dull yellowish tan.

Thanks, the tree is too tall to see the leaves clearly so we are working on the bark alone at this point. I am pretty sure it is the Southern Red but we are ID'ing the local trees for a community project and I am trying to be certain.
Now if only we could persuade a squirrel to go up the tree and send a branch down......

I forgot to say that the end buds of Black Oak can be as long as 1/2 inch(1.27cm) while those on Southern Red Oak will only be as large as 1/4 inch(0.64cm).

If you are going to do the bark test, just do it on a very small section of bark. You don't need to uncover much to see the color clearly. Here's a link to the Virginia Tech web page on Black Oak with a photo showing how they've chipped a small piece of bark off a trunk to show the inner bark color.
http://www.cnr.vt.edu/DENDRO/dendrology/syllabus/factsheet.cfm?ID=39

It's actually common for botanists dealing with forest trees(especially in large tropical forests) where they have no access to leaves or branches because they are so high up to carry a small caliber rifle to shoot twigs off the tree for identification and herbarium collection.

I'd say that there most certainly has to be old twigs, acorn remains, leaves(including probably relatively fresh ones), etc. from this Oak to be used with it's identification. A tree that large is just dropping things all the time from animal damage, storm/wind damage, etc. It might take some extra effort but I'm sure you can find something. Either way good luck!

I neglected to say that this is a prissy fussy neighborhood where leaves, twigs, etc. are never allowed to touch the ground. Anything that may fall is swooped up before civilized folks get up and out in the mornings. The tree is not near my home or I would have been out there myself at 5 am. Asking a groundskeeper to save a twig from one tree would be like trying to hold water in sieve. We searched for acorns and only found one cap in the (always fresh) mulch. The caps on both trees are pretty similar.

From our research we have learned that there are more "Red" characheristics on this tree so I think we are going to go with that one and be done. If anyone want to challenge us they can climb the tree. LOL

LOL