True lilies are perennial plants growing from bulbs, which are made up of loosely over-lapping scales not enclosed in a protective outer coat as, for example, the tulip. They produce erect leafy stems from a few inches to several feet tall topped by a terminal flower or flowers borne on stalks held at varying angles from horizontal to vertical. The seedpod opens at the top and splits into three seed compartments which contain light papery seeds. The shape of the flower varies greatly from massive trumpets to small bell shaped blossoms, but no matter what their form, all true lilies have six petals and six stamens which carry the anthers or pollen bearing organs. Many other plants are called lily, which do not belong to the true lily group (genus Lilium) such as Daylily, Calla lily, Water lily, and Plantain lily.

Here is a list of not true lilies (I’m sure it is not complete):

Arum lily – Zantedeschia aethiopica
Aztec lily – Sprekelia formosissima
Calla lily – Zantedeschia elliottiana
Canna lily – Canna
Daylily – Hemerocallis
Dragon lily – Dracunculus
Jacobean lily – Sprekelia formosissima
Lily of the Valley – Convallaria
Lotus lily – Nelumbo
Magic lily – Lycoris
Peace lily – Spathiphyllum
Peruvian lily – Alstroemeria
Plantain lily – Hosta
Resurrection lily – Lycoris
Snake lily – Dracunculus
Stink lily – Dracunculus
Surprise lily – Lycoris
Sword lily – Gladiolus
Toad lily – Tricyrtis
Voodoo lily – Dracunculus
Water lily – Nymphaeaceae