Lilies are members of the Lilium genus. What could be a simpler answer to the question posed by the title than that? But within that simple description is a wealth of possibilities.
Lilies are typically distinguished by divisions. Here are a few examples:
Division I contains the Asiatic hybrids. The flowers face upward and have no scent. As the name suggests, they're native to Asia where they grow wild and from which the domesticated species have been developed.
Division II encompasses the Martagon lily species. These hybrids are based on L. martagon and L. hansonii, and several are simply stunning. With their small, delicate, curved petals of an amazing variety of styles and colors, they offer an unparalleled floral display.
As an example, of a delicate Martagon, consider the dazzling Mahogany Bell. Scarlet red with tiny dark dots, and a Turk's Cap shape, it would work well as the centerpiece for a fine dining table decoration. Atop a white tablecloth, they provide a brightly colored contrast that strongly draws the eye, just where you want it to be.
Skipping over a few, Division VI houses the Trumpet lilies. Named for their resemblance to the musical instrument, they'll make anyone who owns them break out in song. Their lovely scent, which is even more prominent at night, only adds to their value.
The Black Dragon is a stellar example. Despite the name, these flowers are white, with a delicate yellow throat.
Division VII offers the Oriental hybrids, based on L. auratum and L. speciosum. But the scientific names don't begin to convey how lovely these fragrant lilies are. They're also among the taller types and the petals are typically much longer than those of other divisions.
Picture a pink and white Stargazer, a member of the Oriental division. With its white striped pink petals and lovely green central stamen it offers an image of Hawaii in the home. That makes it perfect for a garden party, a wedding reception, or just to beautify the home.
For comparison, consider the Secret Message, a hybrid of Oriental and Trumpet styles. Its yellow petals have a central orange throat that looks as if it were lightly brushed on by a painter. The message couldn't be clearer. If you want a flower that is both hardy and provides outstanding beauty, this will serve the purpose with flair.
There are several other divisions worthy of mention. But rather than simply name them all, it might be better to concentrate on how any of the divisions can liven up your home, inside or out. So, maybe the better question would be, what's a lily for, really?
All this useful technical and floral display information has a point, of course. That is to show some of the many options that lilies offer for weddings, home decoration, and simply bringing enjoyment to the viewer. What's the point of that? Well, that needs no justification, does it? Beauty is its own reward.