Oak is one of the most popular species for hardwood flooring and often thought of as the traditional choice. Oak is a very hard, heavy, open-grained wood that grows from deciduous and evergreen trees in the United States. It is found in both red and white varieties. Red oak (also known as black oak) has a pinkish cast and is the more popular in a natural finish. White oak has prominent rings and large pores that allow it to stain well in any color.