Diatoms are microscopic algae composed of separate halves, with delicate siliceous cell walls. They're usually single-celled organisms, though some live colonially. They inhabit fresh and salt waters and are among the most abundant of all phytoplankton.
A scanning electron microscope captures the honeycomb shape of the Mexican wildflower seed ( Lamourouxia viscosa ). Many wind dispersed seeds have a honeycomb pattern which allows them to travel more effectively. Image via Rob Kesseler