What Do Adaxial and Abaxial Mean?

The adaxial surface of a leaf or grass blade is the upper surface, which faces toward the axis or stem of the plant. This chlorophyll-rich upper leaf surface is responsible for capturing light needed for photosynthesis. 

The abaxial surface of a leaf or grass blade is the lower surface, which faces away from the plant’s axis or stem. This side of the leaf is responsible for the exchange of gases, such as the absorption of carbon dioxide from the environment and the release of oxygen from photosynthesis.

Because the abaxial and adaxial surfaces of grass reflect light differently from each other, mowing swaths of grass in opposing directions creates lawn stripes.