Last year, I carved out a patch in the vegetable garden, planted some corn kernels, and was very excited when the sprouts emerged. But a few days later, all the sprouts were severed, laying forlornly on their sides where they had fallen. Upon closer inspection, the sprouts had been pulled up and the corn kernels had been chomped off at the base — clearly the work of chipmunk commandos who had infiltrated the garden at the crack of dawn. Chipmunks 1, me 0.
This year, I planted seedlings instead of kernels, crossed my fingers, and hoped for the best. As of yet, there haven’t been any corn massacres, so I’ve been able to watch corn plants grow for the first time — and admire their constituent parts. There is a lot to notice, from the stripy leaves…
… to the beguilingly named tassels and silks. The highly recognizable tassel at the top of every corn plant is the male part of the plant, and consists of about 1,000 spikelets, each containing 3 pollen-producing anthers and their filaments (collectively, the stamens). With 6,000 pollen-producing units on each corn plant, that’s a lot of pollen to be wind dispersed (read more about pollen shed in this great article on “sex in the corn field“).
The silks are the female part of the corn plant. They form at the base of the ear but are most visible at the tip, emerging from the husk. Their job is to catch the pollen and guide it down to the unfertilized corn kernels (ovules) on the ear. Here’s the fascinating part: Each silk is connected to a kernel (or what would be a kernel if successfully pollinated). As not every ovule gets pollinated, most ears produce about 400 to 600 kernels.
You can tell when pollination has occurred because the silks dry up, turn brown, and often fall off. You can also tell when pollination hasn’t been very successful if your ear of corn has missing or misshapen kernels. That’s why it’s important for home gardeners to plant corn in a block rather than a single row, so the pollen has more chance of falling on nearby silks rather than being completely blown away from the row.
I don’t have any photos of pollen on the silks, but this is what the tiny yellow pollen grains look like on a corn leaf, along with some spent anthers (they drop off the tassel after the pollen is shed).
Though corn is pollinated by the wind (anemophily), pollination can also occur with the help of insects (entomophily). Luckily for me, as I was taking photos of the tassels, a bumble bee appeared. Or, more specifically, a female bumble bee appeared–as the females are the only ones to have pollen baskets (corbiculae) on their hind legs.
Perennial Pastimes 