Ferns, mosses and liverworts
It’s wet all along the River Dart in Devon. There are pool of stagnant water in channels where the River used to run but no longer does. There are small cliffs, steep slopes and large established trees so that the sun never really reaches the ground with full power and the humidity is high all year round. Looking down, everything is green. Then I realise that there aren’t any flowers: all the plants surrounding me are so-called ‘primitive’ ones and are descended from ancestors which existed before flowers evolved.
There are mosses under my feet:
Mosses don’t have any circulatory system to take water from one part to another or to take nutrients back. They need to be damp and can hold an extraordinary amount of water. Their bodies are so simple yet so effective.
There are liverworts, at least that’s what I think this is. Liverworts have been on Earth since before plants evolved roots. This one has lobes just like a liver:
There are ferns:
Ferns do have proper circulation, with a vascular system which has specialised cells to transport water and nutrients, so ferns can be much bigger and raised off the ground. Ferns really do put mosses and liverworts in the shade.