Following is my brother's comments on Red Oak:

"The next time you look at a piece if red oak, look at the growth rings.
As you know 1 growth ring consists of actually 2 rings, a light color and a dark colored ring. The light color is called “spring wood” or “early wood” which means this is the growth that was put on in the spring and early summer.
This is usually but not always the widest part of the ring (fastest growing time of year). This is very prevalent in pines. Any way the dark color is called “late wood” or “summer wood”. It is dark because growth is slower and the wood cells are more compacted. In red oak the summerwood is full of tiny holes, which run the entire length of the board, which would cause leakage. If you look at a white oak board you will notice the same type of thing but the tiny holes look like they have a plug in them.
These“plugs” are called tylosis. This is why white oak is ideal for whiskey barrels because they seal so good.

Not sure about teak. If you look at the cross section of a piece of wood with a 10x magnifying class you will see a lot. You can actually see the individual xylem cells as well as all the other characteristics I just mentioned."