Friday, 25 May, 2012

This image shows a very small portion of a cotton flower magnified more than 500 times. The spike-covered orbs are cotton pollen grains stuck to the papillar surface of the stigma, a sticky surface with finger-like projections. The stigma is located at the very top of the pistil, which is the female reproductive structure of [...]

Many of the tastiest crops can’t pollinate themselves: melons, cucumbers, strawberries, almonds, cacao. But pollinators — both native and managed — are under threat from diseases and pesticides. They aren’t finding enough to eat. Their colonies are dying. What can we do?

It’s one of the biggest puzzles of paleontology: Why did North America’s large mammals go extinct shortly after the glaciers melted about 15k years ago? New study suggests that hunters get the credit — or blame.

The luscious aroma of flowers attracts lovers, and the biological role of that smell is similar: to attract pollinators. “Plants need to attract insects, bats and hummingbirds to transfer the pollen and create fertile seeds,” says Hugh Iltis, professor emeritus of botany at UW-Madison. Pollination is the transfer of pollen (the plant equivalent of sperm) [...]

Tissue, please… In honor of the sneezin’ season, this CSI is common ragweed pollen as seen under a microscope. Ragweed pollen is the principal cause of hay fever and can also trigger asthma. But for all the itchy throats and watery eyes, this tough little plant is just trying to survive. The common ragweed is [...]

This CSI is a picture of a pollen grain from an extinct group known as triprojectates. This particular beast, Triprojectus unicus, was common about 65 million years ago in the Late Cretaceous, when the dinosaurs still ruled the roost. The nasty-looking recurved spines may have allowed the pollen grains to hitch rides on passing insects. [...]