The tiger lily (Lilium lancifolium Thunberg) is native to eastern Asia--China, Korea, and Japan. Tiger lilies have been cultivated for centuries in the Orient, but only for a little over 200 years in Europe and the Americas. The lily was a puzzle when first introduced to western gardeners; the stalks produced large beautiful orange flowers, but no seeds.
The tiger lily grows from a bulb covered with leaf-like scales. A single flowering stem arises from the center of the bulb.
The stem has alternate, lance-shaped leaves and terminates with the flowers. After blooming in the summer, the stem dies back down to the bulb.
Even though tiger lilies did not produce seeds, gardeners found they could propagate the plants. In the axils of the upper leaves, those closest to the flowers, the tiger lily produces bulbils. Removed and potted, the bulbils become lily bulbs.
Gardeners also discovered that scales removed from fully-grown bulbs and potted would produce bulblets which also grow into lily bulbs. By happenstance, the first tiger lily known to western gardeners was a triploid variety (3 sets of chromosomes). Other varieties were later found that were diploid (2 sets of chromosomes) and could produce seeds.
For all the beauty and ease of cultivation, tiger lilies received a bad reputation. The plants are highly susceptible to lily mosaic virus. The disease does not affect tiger lilies, but the plants served as a reservoir for the virus. Aphids that visit an infected tiger lily vector the virus to other Lilium species that decline and die.
Lily mosaic virus spreads throughout the plant--leaves, flowers, bulbs, bulbils, and bulblets all carry the viral particles with one notable exception. Seeds from the diploid tiger lilies are protected from the virus. (Note: All tiger lilies sold by nurseries today must be mosaic virus-free. This is the same virus that caused the tulip streaking which started a speculation bubble.
