GERD GUENTHER / SCIENCE PHOTO LIBRARY GERD GUENTHER / SCIENCE PHOTO LIBRARY
Microscope footage of spores being released from the sporangia of a male fern (Dryopteris filix-mas). The sporangia were taken from a sorus on the underside of a fern frond, and embedded in anhydrous glycerol. Due to the anhydrous conditions, the mature sporangia start to open and begin to release the spores, ending with a rapid movement to catapult the spores away. The movement is initiated by a rim of thick-walled cells, the annulus (light orange). Dehydration causes these water-filled cells to dry out, contracting and straightening, ejecting the spores. In dry air this is a very rapid process that can fling the spores away from the plant. In this preparation, the movement is softened and slowed by the surrounding glycerol, to show the sequence under controlled conditions. Filmed with differential interference contrast illumination. Captured field width: 0.5mm. This footage has been sped up 400% (x4).
Model release not required. Property release not required.