Wood Sorrel growing on a tree, taken 6 years ago
This little clump of Wood Sorrel is getting enough nutrients from the moss to be able to grow in the fork of the tree. Seen close to the path on Greenway Bank Country Park.
Wood Sorrel (Oxalis acetosella) is one of the characteristic early spring-flowering plants of the woodland floor, often appearing alongside Wood Anemones, Bluebells and Ramsons. It is, when flowering with certain other species, used as an Ancient Woodland Indicator. It can be found across much of the UK but is less common in the east of the country. The flowers appear in April and May and are hermaphrodite, in that they have both male and female organs and are pollinated by Bees, flies and a type of self-pollination known as Cleistogomy, meaning that the flowers can pollinate without the flowers opening. During periods of rain and at night the flowers and leaves will close in on themselves. Both the leaves and flowers are edible, usually eaten raw as part of a salad.
Mosses belong to a group of plants known as Bryophytes which are the oldest plants in the world, dating back at least 400 million years with over 600 species found in Britain and Ireland alone. They are conspicuous, low growing and rootless plants that absorb nutrients from the water that either runs over them or they hold like a sponge. They are considered a "pioneer" plant, taking over rock faces and wet areas and creating a humus layer thus allowing other plants to germinate and gain a foothold.
Mosses are asexual, carrying both male and female reproductive organs, after fertilisation these organs produce a tiny capsule that, when ripe, releases thousands of spores which go on to reproduce the next generation.