Liverwort (Pellia epiphylla) spores. Light micrograph of a section through spores (round) from a common pellia liverwort, showing the elaters (long) attached to them. Elaters are specialised cells that are hygroscopic (absorb water easily) and therefore change shape in response to the presence or lack of water. Here, they aid spore distribution. Magnification: x13 when printed 10 centimetres wide.