Pollen of Artemisia (Asteraceae). Pollen grains were extracted and embedded in 2,2-thiodiethanol medium and imaged in a photon-counting mode on an Olympus FV1000 confocal microscope equipped with a 100x/1.4 oil immersion objective. The 3D image stack was surface-rendered using Osirix software. Sample preparation and imaging By Stanislav Vitha (MIC), rendering by Amen Zwa (Gannontech Inc.). Scale bar = 10 micrometers.