There is no age limit but I would add the information in the comments section. It's ok if all you know is the genus. Type the genus name into the plant name entry. When you are typing a name the system will try to match it with the database. If there is a generic genus entry for that plant you can select that or just leave it the without attaching to the database. Here is an example I did for Hibiscus. The top one is not attached to the database the second one is.
