Darkfield image of spherical colonies of Nostoc commune, a bluegreen alga. Nostoc commune is a terrestrial species of cyanobacteria that in 1988 was found to harbor a previously unidentified UV-A/B ab...

A brightfield, multi-focus stack image of a sorus of Asplenium trichomanes (maidenhair spleenwort), a small fern. A sorus is a cluster of sporangia, which produce and contain spores. Honorable Menti...