Peas

So you think you know what a pea is? A spherical green seed that grows in a group of other peas inside a pod. In order to get at the peas, you need to shell them, by splitting the pod into its two natural halves, which look like little sailboats. Indeed, in ancient Rome, they used the same word, phasellus, for a small sailboat or a kidney bean.* Ancient usage makes it clear that the word referred to the kidney bean and not the pea, which is pisum in Latin, whence the species name for the garden pea, Pisum sativum.