Lilies are bulb plants that produce large ornamental flowers used as garden specimens and long-lasting cut flowers. They are available in a wide variety of colors, sizes and fragrances. Lilies have a unique physiology, and the ability to reproduce by bulbs or seeds. Lilies can be planted in a group or spaced separately in the garden so you can see the individual beauty of each flower and stem.
The inflorescence is the entire part of the lily plant where the flowers are produced. The inflorescence can be either a raceme or an umbrel type. In a raceme inflorescence, the flowers are borne on a series of flower stalks that appear up and down the stem. In an umbrel inflorescence, the flower stalks grow from a central point at the top of the stem.
The flowers of lilies can be one of three types: bowl shaped, trumpet shaped or turk's cap where the petals fold backwards against the stem when the flower is fully open.
The lily seed capsule is divided into three parts by paper-like walls with the seeds stacked inside. The flat seeds have "wings," or thin raised areas along the sides of the seeds that aid in wind dispersal. A lily seed is fertile if you can see a dark line, which is the embryo, in the middle of the seed.
Stems and Leaves
The stem grows straight up from the top of the bulb or may travel underground before emerging from the ground, depending on the type of lily. Leaves can be whorled, alternate or grow sporadically along the stem.
On the surface of the bulb are fleshy scales that store energy for the next year's growth. Located at the bottom of the inside of the bulb is the basal plate or axis that produces the scales, roots and buds for new growth. In American and European lilies, new bulbs, or bulblets, form inside the bulb above the basal plate. The bulblets attach themselves to the new stem as it rises from the bulb, and they settle just below the soils surface. As the roots of the bulblets grow, they pull the newly formed bulbs further into the ground for stability and protection from the elements. In some species, however, the stem travels from the bulb and develops new bulblets along the stem away from the main bulb.
Lilies have two types of roots: basal roots that extend from the bottom of the bulb (the basal roots are for stability and pull the bulb deeper into the ground); and stem roots located above the bulb along the stem (these are the feeding roots). This is why lily bulbs always need to be planted deep enough for the stem roots to develop.