From a botanical standpoint, the term "lily" correctly refers to plants within the genus Lilium. These are herbaceous, perennial plants that grow from bulbs, which are composed of fleshy, overlapping scales without a protective outer coating. True lilies are characterized by their large, often fragrant flowers that consist of six tepals (three petals and three sepals that look identical), six anthers with prominent pollen, and a single superior ovary. This specific floral structure is a key identifier for plants within this genus, distinguishing them from common misnomers like daylilies (Hemerocallis) or water lilies (Nymphaeaceae).
Asiatic hybrids are among the earliest to bloom and are derived from species native to East Asia. They are characterized by their upright flowers, wide range of vibrant colors (including yellows, oranges, pinks, reds, and whites), and generally lack a strong fragrance. These lilies are known for their hardiness and are well-suited for beginner gardeners. Their flowers can be outward, upward, or pendant-facing. They propagate primarily through division of their bulbs and bulblets that form along the underground stem.
Martagon hybrids, derived from species like Lilium martagon, are known for their Turk's-cap style flowers, where the tepals strongly recurve backwards towards the stem. They produce numerous, smaller flowers on tall, whorled stems and thrive in dappled shade, making them excellent woodland garden plants. They are slower to establish and can be sensitive to virus diseases, but they are valued for their unique, graceful appearance and ability to naturalize.
This division includes hybrids and cultivars derived from European species, most notably the Madonna Lily (Lilium candidum). These lilies are celebrated for their pure white, trumpet-shaped flowers and powerful fragrance. They have specific cultivation requirements, preferring their bulbs to be planted very shallowly and requiring excellent drainage. Unlike most lilies, Madonna lilies can produce a basal rosette of leaves through the winter.
American hybrids are developed from native North American species, such as Lilium pardalinum (Leopard lily) and Lilium canadense. They typically feature Turk's-cap shaped flowers in warm hues of yellow, orange, and red, often with prominent spotting. These lilies are adapted to specific ecological niches, often preferring moist, acidic soils and partial shade, and they are excellent for naturalizing in appropriate climates.
This group is defined by hybrids involving the Easter Lily (Lilium longiflorum). They are characterized by their pure white, large, trumpet-shaped flowers that are intensely fragrant. While widely grown as a forced pot plant for religious holidays, they are also garden plants in warmer climates. They are not as cold-hardy as other divisions and are susceptible to virus diseases.
This is a large and diverse group, including hybrids from Asian species like Lilium regale. The flowers are trumpet-shaped or bowl-shaped and often highly fragrant. Aurelian hybrids, a subset, are known for their tall stature, numerous outward or pendant flowers, and tolerance for a wider range of soil conditions. They are a cornerstone of the midsummer garden, providing height and spectacular blooms.
Derived from Japanese species like Lilium speciosum and Lilium auratum, Oriental hybrids are famous for their large, breathtakingly beautiful, and intensely fragrant flowers. They often have striking patterns, spots, and contrasting edges on their broad tepals. Blooming later than most, they extend the lily season. They require well-drained, acidic soil and can be less winter-hardy, often benefiting from mulch protection.
