Pillwort: Time-lapse sporocarp explosion

26th August 2020

Following on from the pillwort monitoring on Skipwith NNR in August 2020, we were keen to find out more about the reproductive methods of this rare and fascinating aquatic fern.

After a really successful and productive monitoring visit to this important FHT ‘Flagship Ponds’ site with the aid of FHT friend and collaborator Dr Barry Wright, the pillwort journey was to continue.  Utilising the latest technology, Barry was keen to do some experiments with the pillwort sporocarps. After collecting a few ripe specimen, he set up a time lapse camera back at base to see if it was possible to capture footage of the pills exploding. The result..?

CLICK ON THE IMAGE BELOW!

This sequence was taken at 1 frame/30 seconds. This condenses 15 minutes of real time to one second of video and ran for 11 hours.

The micro-spores are the male organs that contain active motile sperm cells. The mega-spores are the female organs that will eventually produce a new plant once fertilised by sperm from a micro-spore.

The micro-spores rupture to release the sperm that swim through the water and enter the mega-spore through the cone-shaped top of the structure. Once fertilised this cone grows and turns green like a clown’s wig before pushing out a rhizome one way (white) and a first frond (green) the other. The rhizome develops roots and the plant eventually sinks to the bottom of the pond and roots, or may get stranded on the moist substrate if the pond dries out.

Once again, thanks to Dr Barry Wright for his tireless enthusiasm for pillwort and for help with monitoring this rare and fascinating fern.

To find out more click on the links below: