Corn plants (Zea mays) possess distinct reproductive structures that function as flowers. While not resembling typical garden blooms, these structures are essential for the plant’s reproduction and the formation of corn kernels. Corn is a monoecious plant, meaning it produces separate male and female flowers on the same plant.
The Tassel: Corn’s Male Flower
The tassel is the male flower of the corn plant, located at the top of the stalk. It appears as a branched, feathery structure. Each tassel comprises numerous tiny male florets, organized into spikelets. These spikelets contain anthers, which produce and release pollen. Pollen shedding from the tassel typically occurs over a period of 10 to 14 days.
The Ear and Silk: Corn’s Female Flower
The female flower of the corn plant develops into the ear, positioned lower on the stalk. This developing ear is encased by protective layers of modified leaves known as husks. Emerging from the tip of these husks are the silks, which are the functional stigmas of the female flowers. Each strand of silk is connected to a potential kernel, or ovule, on the cob. The silks are receptive to pollen, and their primary function is to capture pollen grains for fertilization.
The Pollination Process
Corn pollination primarily relies on wind to transfer pollen from the tassels to the silks; pollen grains, released from the tassel, drift through the air and land on the sticky surface of the silks. A single pollen grain landing on a silk initiates the growth of a pollen tube, which grows down the length of the silk, reaching the ovule within 12 to 28 hours. Fertilization occurs when the male nuclei from the pollen grain fuse with the female nuclei within the ovule, a process known as double fertilization. Each successful fertilization of an ovule by a pollen grain results in the development of a single corn kernel; if a silk does not receive pollen, the ovule it is connected to will not develop into a kernel, leading to missing or underdeveloped kernels on the ear. Therefore, successful and widespread pollination is crucial for the formation of a full and well-developed ear of corn.