Scanning electron microscope (SEM) image of the seeds and replum of a thale cress plant (Arabidopsis thaliana). The replum (orange) is a thin and persistent division of the fruit of some members of the Brassica family, dividing the two halves of a pod-like structure called a silique. A. thaliana is a popular biological research organism, and was the first plant to have its genome sequenced.