You're mistaken. :-) Oak does.
Here, look at this:
Figure such as is visible in the image I referenced above will appear in oak, regardless of how close together the grain lines are. It's caused by physical structures in the tree that appear on their edges when the board is flatsawn (whence the short, dark lines between the grain on flatsawn oak), and on their faces when the board is quartersawn (as shown in the image referenced above). These structures are present in all North American species of oak, and are visible regardless of the manner in which the wood is sawn, or the separation between the grain lines, or any other factor. That they are *not* visible in Don's photograph is incontrovertible proof that the wood in Don's photograph is unquestionably *not* oak. And neither are they obscured by the stain: these ray structures do not absorb stain nearly as readily as the rest of the wood, and staining makes them stand out even more.
As I've noted several times before in this thread, they are *often* confused. Ash is frequently used as a lower-cost substitute for oak, because most people can't tell the difference. Both are widely used in furniture making.