Hardwood flooring comes in many different varieties, offering a huge range of colors and grain patterns to choose from. Some examples of popular hardwood flooring species include walnut, cherry, red oak, white oak, maple, hickory, ash, birch, beech, teak, and bamboo. Some of these species are native to the U.S., while others must be imported from abroad, potentially impacting the cost. They also vary in hardness, which is ranked using a scale called the “Janka Hardness Rating.” For example, walnut has a Janka Hardness Rating of 1010, making it slightly softer than birch, which has a Janka Hardness Rating of 1260.