Lin, this only applies to general entries that aren't parent plant entries. If there is a parent plant entry, the underlined name at the top of every entry for the genus will be the name of a custom database rather than the name of the genus. When you click on that name, you'll be taken to the home page of the custom database and will have a choice of the full alphabetical list of plants or the generic (parent plant) entry. You can see the choices on the home page of this custom database:
The Roses Database