In botany, a hilum (pronounced /ˈhaɪləm/) is a scar or mark left on a seed coat by the former attachment to the ovary wall or to the funiculus (which in turn attaches to the ovary wall). On a bean seed, the hilum is called the 'eye'. In botany, a hilum (pronounced /ˈhaɪləm/) is a scar or mark left on a seed coat by the former attachment to the ovary wall or to the funiculus (which in turn attaches to the ovary wall). On a bean seed, the hilum is called the 'eye'. For some species of fungus, the hilum is the microscopic indentation left on a spore when it separates from the sterigma of the basidium.