What Is the Method of Seed Dispersal for the Calla Lily?

Animal Dispersal

• The large white wrapping around a calla lily is not its true flower, but a spathe, which is an adapted leaf. Within the white spathe is a spadix spike that holds numerous female and male flowers. As the flowers are pollinated, the spathe eventually dies back and reveals berries full of seeds. Birds are often attracted to the yellow fruits and eat them voraciously. As the birds move on, they disperse the seeds through their feces. Birds may also move the seeds by mouth as they travel -- they drop the fruits before eating them, allowing the fruit to rot away naturally to reveal the seeds. The birds' digestive system does not harm the seeds and allows the calla lily to move quickly into new growing areas.

Water Dispersal

• Calla lily is versatile when it comes to where it will grow -- it vigorously populates areas next to ponds and other waterways where the soil is constantly moist. As a result, many fruits and seeds end up in the water. The benefit to water dispersal is traveling distance. As the fruits move with the current, they populate areas downstream that are free from other plant competition. The fruits often travel a long way in water until they settle in a prime location. Birds may also spot the fruits in the water, picking them up and moving them even further.

Alternative Reproduction

• Although seed dispersal is one of the ways calla lily reproduces, it also spreads through underground stems, called rhizomes. Acting as storage organs with numerous buds on the surface, rhizomes grow new stems and leaves for the calla as they swell in size from nutrient and moisture absorption. These hidden stems are easily divided to produce more plants in the garden.

Benefits

• Using animals and water as seed dispersal strategies allows the tiny seeds to spread successfully. Calla seeds do not germinate and grow successfully if they are buried too deep in the soil. Bird droppings and water movement allow the seeds to remain close to the soil surface for proper growth. The plant's spathe is another benefit for seed dispersal -- its bright white attracts pollinators and curious birds. Calla lily has been so successful at reproduction that it's considered invasive in some areas.