Yellow asiatic lilyCredit: wordspeller

Exploring A Genus Of Lilies

The Lilium genus contains over one hundred true lilies and is botanically classified under the Liliaceae family of plants, as originated by Linnaeus. All species lilies and their many hybrid versions belong to this genus.

There are nine divisions in the horticultural classification of lilies. The list was first developed in 1963 by the Lily Society of Great Britain and is maintained by the International Lily Register.  

The largest division of lilies is (IX) True Species. It features original Lilium species as found naturally in the wild. All Lilium species – with the exception of Lilium zairii in Africa –  are native to the northern hemisphere.

The nine divisions of classification are:

I       Asiatic hybrids
II     Martagon hybrids
III    Candidum/European hybrids
IV    American hybrids
V      Longiflorum and formosanum hybrids
VI    Trumpet and Aurelian hybrids
VII   Oriental hybrids
VIII  Interdivisional hybrids
IX    True species

What Are Lilies?

The word Lilium is a Latin name that is derived from the Greek word leirion – meaning 'lily'. It is a term solely used in conjunction with true lilies, such as Lilium regale, Lilium henryi and Lilium longiflorum, and is not related to other plant species bearing the common name of 'lily'. Plants like African Blue Lily (Agapanthus africanus), Amazon Lily (Eucharis grandiflora) and Belladonna Lily (Amaryllis belladonna) are referred to as false lilies.

Lilies are monocotyledons and are moderate to fast growing perennials. Each species has their own soil preference, favoring full sun and/or partial shade, and can either be very difficult or very easy to cultivate . . . or somewhere in between!

In the garden, these flowers combine well with low growing shrubs, perennials and flowering annuals. Their elegant blooms can be cut and arranged in vases to adorn table settings in the home and provide sweet fragrance to living areas.

Lilies are suitable for tropical-style plantings, rock and alpine gardens, and remain cottage gardening favorites, accompanying old-fashioned roses, English Lavender and Marigold.

A recognized symbol of purity, lilies are some of the most beautiful and historic flowers in the world. Valued by cultures past and present, many Lilium species inhabit temperate forests, fields and swamps on various continents, and are highly endangered today.

Lilium speciosum cultivarCredit: wordspeller

The Structure Of Lilies

• Bulbs

Made up of succulent, starchy scales, lily bulbs have no outer protective skin or dormancy period. These characteristics make lilies highly unique to other popular bulb species, such as the tulip, gladioli and daffodil. 

Lilies have five bulb types:

•  stoloniferous
•  stoloniferous stemmed (stoloniform)
•  concentric
•  rhizomatous, and
•  sub-rhizomatous.

Lilium bulbs consist of a collection of scales and roots attached to a basal plate, and can differ in shape and color. These two aspects can help identify one species from another. Scale color can often change when exposed to sunlight and are thick modified leaves of moist, starchy consistency.

The main role of bulbs is to store food reserves for future growth. The basal roots of the bulb provide good anchorage in the soil for lilies and help to pull it further down into the ground. 

Depending on the species, some bulbs either produce roots from the bulb base or are stem rooting, with roots growing from both the bulb and lower stem. Stem roots can be found in many species, aiding plant stability and nourishment.

• Leaves

Widely varying in height, lilies are also diverse in their foliage color and shape. From stems of purple to grey-green, their leaves are generally arranged in scattered, alternative or whorled patterns, and are mostly linear and lanceolate (lance-shaped) in appearance.

A small number of Lilium species have leaves that resemble thin, grass-like blades, eg Lilium formosanum, while others, like Lilium auratum (pictured below), have quite broad-shaped leaves.

Texture is another unique factor in certain number of these species. Leaf surfaces can be glossy and smooth, or covered with many fine, silvery hairs. In the leaf axils of some lilies, bulbils can also develop and can be used to vegetatively propagate the same species, eg Lilium lancifolium.

Gold-banded Lily (Lilium auratum)Credit: wordspeller

• Flowers

Inflorescences (or flower heads) are lilies most prominent feature. While some produce only a single flower every year, many lilies carry several flowers or more, arranged in a number of patterns at the head of the plant.

The four different inflorescence patterns are:

•  umbel
•  composite umbel
•  raceme, and
•  composite raceme.

Lily blooms are distinctively shaped, and are described as being turk's cap, trumpet or bowl-shaped. These can be spotted or fragrant, both or neither. On the floral interiors of lilies, there is sometimes a raised texture across the petal surface – these are called papillae – Lilium speciosum is one lily species that displays these.

The bright colors that make lilies so vibrant and beautiful are created by an assortment of different pigments in their tepals – carotene (for yellow), flavine (for light yellow) and anthocyanins (for reds and oranges). Each Lilium flower consists of six tepals, ie three sepals and three petals.

Their flowers also contain the reproductive section of the plant and when fertilization has occurred, the tepals gradually die away, to reveal young, green seed pods. These oblong pods consist of two rows of hundreds of seeds in each of the three cells, from which new lilies can later grow.

Lilium henryi cultivarCredit: wordspeller

Joining A Society

Plant societies are invaluable organizations, enabling the sharing of information on all aspects of a particular genus. Some societies have been established for decades and provide access to seed and/or bulbs of a wide variety of flower species and hybrids. Newsletters are produced throughout the year and annual shows give members the chance to display their lilies for official judging. 

The world's largest society that focuses on lilies is the North American Lily Society (or NALS). It is a not-for-profit organization that offers an annual seed exchange and is popular with Lilium growers, specialists and enthusiasts from many different countries. Becoming a member of the NALS is an ideal way of obtaining seed of lesser known species that are otherwise impossible, or hard to find elsewhere.

Next article: Lilies: A Favorite in Floristry