The Anatomy Of The Lily
All lily plants have a reasonably long life span and they generally survive over several years. Every year, the plants give rise to a new stem, which emerges from its underground bulb – the plant’s storage organ. The flowers of lily may appear in a variety of angles on the stalk, which may bear one or many blooms. Interestingly, the flower parts of lily appear in either sets of three or six. This pattern is universal in the family Liliaceae.
The various parts of a lily plant as well as their respective functions are discussed in brief below. A normal lily plant comprises the underground bulb, roots, leaves, stem and flowers.
The lily bulb
The bulb of a lily plant is made up of solid, plump scales that stores nutrients for the plant’s growth in the following season. The bulb of a lily plant comprises a short stem, which is also known as axis or the basal plate. The fleshy scales are attached to this stem. In fact, the axis is the most vital part of the lily bulb, as it not only generates the roots and scales, but also the buds that ensure new growth. The scales are basically modified leaves, very thick and short. They are responsible for supplying the plant with nutrients for growth development till such a time when they have enough leaf area as well as the root system starts its normal functions. The color of the scales is significant, as it helps one to identify the lily species. However, the color of the scales may alter when exposed to light.
There are two common types of lily bulbs – rhizomatous and concentric. It has been seen that the rhizomatous bulbs develop best in the species having their origin in eastern America, such as Lilium michiganense, Lilium canadense and Lilium superbum. A section of the bulb is called the daughter bulb, which develops at the terminal of a flat, scaleless branch that emerges from the mother bulb. The daughter bulb produces flowers a year after their emergence and also gives rise to another daughter bulb. Lilies possessing these features are generally found growing in damp meadow or marshy lands where the soil is hardly ever distributed. Such kind of habitat makes the lilies look for fresh soil every year, thereby resulting in the formation of large colonies.
On the other hand, in concentric type lily bulbs, the axis preserves its shape and position year after year. While the bulb stays concentric and its scales are arranged in the region of a short vertically growing stem. In this case, the daughter bulb forms inside the mother bulb as well as near the axis. In a number of instances, there may be two or additional daughter bulbs, which form in the region of the axis. Sometimes, the daughter bulbs of concentric type lily bulbs may also get detached, but continue to remain crowded. Nearly all species of Asiatic and European lilies have concentric type bulbs. For instance, in species like Lilium nepalense, Lilium lankongense and Lilium wilsonii, the stems actually travel for some distance underground before they emerge above the soil surface. These stems produce bulblets that are located quite far from the mother bulb. This pattern is known as stoloniferous.
In addition to the above mentioned types of lily bulbs, a modification of the rhizomatous variety is found in the species having their origin in western America, such as Lilium parryi and Lilium pardalinum. In this case, the chubby perennial rootstock or rhizome is swathed with scales. In this case, the rhizome may measure up to 2.5 cm (1 inch) across and its oldest part may be many years old. This type of growth pattern is beneficial in soils that are often disturbed, such as those along the stream banks, which are natural habitats of lilies. This is because even if the rhizome is washed away due to erosion, the leftover parts can produce new plants again.
As in the case with other plants, the lily roots serve two vital purposes – first, to absorb water and nutrients from the soil and, second, to give the plants a firm anchorage. The basal roots of lily, which spread out from the bulbs’ base are basically the feeding roots and, hence, are extremely vital in the plant’s life. It is important to bear in mind that you should always plant the bulbs at a sufficient depth with a view to give enough space for development of ample stem roots.
The stem and leaves
The length of a lily’s flowering stem may vary depending on the species and hybrids. For instance, a mature flowering stem of Lilium nanum or any other species belonging to the high alpine may be just few inches tall, while that of Lilium leucanthum var. centifolium or the Lilium superbum may grow up to a height of 250 cm (8 feet). In a number of lily species and hybrids, the stem rises from the bulb. Lilium martagon and Lilium regale or the regal lilies are best examples of this type of flowering stems. On the other hand, the stems travel for some distance underground before emerging above the soil surface, as in the case of Lilium nepalense and Lilium lankongense. Even the color of lily stems differs from pale green to deep purple. In fact, the stem color of plants belonging to the same species may vary in a single population.
The leaves of lily plants also vary from being slender, grassy foliage as in Lilium pumilum to the wide, lance-shaped leaves of Lilium auratum var. platyphyllum. In a number of lily species like Lilium taliense, the stems are naked akin to those of asparagus and they grow up to a height of 30 cm (12 inches) or sometimes even taller before the leaves spread out.
Lilium hansonii, Lilium martagon as well as their hybrids and many lilies having their origin in North America produce their leaves in standard whorls surrounding the stems with a certain space between the leaves. At times, some leaves appear in whorls, while other are spread out the length of the stem. In nearly all other lily species and hybrids, such as the Oriental and trumpet lilies, the leaves are displayed alternately. This type of leaf arrangement can also be seen in Lilium candidum and Lilium x testaceum. However, the size of their leaves become smaller as we move upward from the base of the stem.
As in the case of other plants, the primary job of lily leaves is to make food, which is subsequently stored in the bulb for the plant’s growth in the next season. Therefore, ensuring that the food-manufacturing part of the plant remains at its optimal efficiency and for the maximum duration possible is a key concern for all lily growers.
Many lily species as well as hybrids produce small purple hued bulbils (small swollen buds) in their leaf axils. If you take away the flower buds from the stems quite early in their development stage, you will notice additional as well as larger bulbils on the plant. In fact, this is considered to be an alternate or back-up reproductive strategy and it is effective when you don’t have seeds to propagate the plants. The lily species called Lilium lancifolium or Lilium tigrinum are known for producing bulbils. When the bulbils come in contact with soil, they can give rise to new plants that are similar to their parents in all aspects.
In the case of some lily species and hybrids, the portion of the stem lying underground can produce bulblets. In fact, the stem roots that appear between the surface of the soil and lily bulbs are feeding roots and are vital for the plants’ growth.
When we use the term inflorescence we actually talk about the flower head or all the parts of a plant that bear the flower. In the case of the lily, the inflorescence may include an umbel, a raceme or just a solitary terminal flower. Precisely speaking, the raceme comprises the series of flowering stalks the length of the stem and each flower stalk bearing one or several flowers at their terminal. In the case of an umbel, the entire flower stalks emerge from one common spot on the stem. The flower stalks of lily, which are also known as pedicels, may have branches or be un-branched.
Lilies bear flowers having forms as well as colors. In fact, such diversity adds to the appeal and attractiveness of the genus to a great deal. The basic forms of lily flowers include trumpet, Turk’s cap and bowl shaped.
Flowers that have the Turk’s cap shape are hanging or suspended and their petals are reflexed – curving backward in the direction of the stalk. Sometimes this form of lily flowers is also referred to as the martagon form. This is because the European species Lilium martagon (also called the Turk’s cap) is the best example of this form of lilies.
On the other hand, trumpet form lilies are found in various shapes, usually having a somewhat slender conical throat region that spread gradually outward in the direction of the petals’ tip. In most cases, the petal tips may be somewhat reflexed. The best examples of trumpet shaped lilies include Lilium regale or the regal lily and Lilium longiflorum (Easter lily).
The third form, bowel-shaped lily flowers is further open compared to the trumpet-shaped flowers. The petal tips of this form of flowers are slightly reflexed, but not to the extent seen in the turk’s cap form. A good example of this form of lily flowers is the Lilium auratum or the gold brand lily.
Lily species can also be distinguished by the carriage of their flowers. For instance, the flowers may appear erect, outfacing, up-facing or even pendent.
Each lily flower has six stamens – the male reproductive organs. These stamens are made up of thin stalks, often referred to as filaments, having anthers or organs that bear the pollens at their tips. The color of lily pollens differs from light yellow to deep brown. The difference depends on the species and hybrids of lilies. At the center of the flower, there is a pistil – the female reproductive parts. The pistils are made up of the ovary at their base – the place where seeds are formed, an elongated style and a stigma having three lobes at the tips – the place where the pollens get fixed.
Together the petals and sepals of the flower are known as tepals. In the case of lily flowers, there is a slender groove at the base of each tepal which contains nectar and, hence, is also referred to as nectar groove. The flowers secrete their nectar in this groove with a view to draw pollinating insects and birds. However, a number of lily species as well as hybrids do not have any nectar groove.
The color of the lily flowers is most conspicuous and a casual observer will notice it readily. Lily flowers come in a variety of colors including various shades of red and yellow. However, you will never see a blue lily flower.
The seed capsule
The seed capsules of lily species and hybrids have different shapes. The form of these seed capsules may vary from the comparatively small capsule produced by the Madonna lily (Lilium candidum) to the elongated, slender capsules produced by Lilium formosanum. Irrespective of their forms, all types of lily seed capsules are separated into three two-part segments by paper-like thin dividing walls. Inside each segment, you will find several flat seeds that are heaped in a manner similar to corns in a wrapper.
As mentioned above, irrespective of the species or hybrids, lily seeds have a flat form. In some cases, as in that of Lilium auratum, the seeds come with large “wings”, which are basically the papery borders that help the seeds to be dispersed by wind. On the other hand, the seeds of Lilium polyphyllum come with insignificant wing tissue. In seeds that are fertile, the embryo or the future plant comes into view as a line across the endosperm, which is the darker hued mass located in the core of a lily seed.