Oat (Avena sativa) flour is made from ground oats. It is unique among cereal flours as it contains no gluten. If used alone in a recipe, the resulting baked goods will not rise or hold together. Oatmeal cookies are an example. Oats contain lipids and the flour can become rancid, so it is advisable to use flour which is as fresh as possible. The flour may be stored in airtight containers in a cool, dry place. Freezing may be used to extend the shelf life of the flour. The SEM micrograph shows small oval and globular oat starch granules in addition to larger ground endosperm particles. Enhanced SEM. Image width: 160 micrometers. Magnification: 625x if the image is printed 10 cm wide. Bar in the right lower corner: 20 micrometers.