Wood-sorrel will grow in very shady places in the woods, it does live in Ninewells wood and there was a very small patch of it growing in my bit of Ninewells wood, however since we removed all the Corsican Pines, I have not seen it. Possibly the disruption caused by the felling and subsequent clearing of the brash removed this very small colony. This is why in an ideal world clear felling should be avoided, however this option was not open to us, we could only obtain a felling licence for clearfell and to be honest that is what I would have opted for as it made considerably more economic sense……. Sorry Mr Sorrel.
Wood-sorrel is another one of the plants which indicates that a woodland is in the ‘ancient woodland’ category, which is why I am a bit unhappy about possibly loosing it from my own patch of woodland, although it is to be found quite nearby in other parts of Ninewells wood and it is quite common along the Wye valley.
This is a quote from another web site which was sent to me in response to my comment that the flowers are cleistogamous. Evidently this is only the case at the end of the season. ‘Wood sorrel rushes to bloom early in the spring while other vegetation is still growing and there is plenty light around, and it is easy for nectar-hunting plants to find the plant’s large flowers. Later in the summer the plant refrains from producing large open flowers in favour of cleistogamous flowers that do not open and resemble buds. These summer flowers are self-pollinating but the seeds usually develop well.’
The flowers are cleistogamous, that is, they undergo pollination and fertilisation before the flower opens. The plant can also spread by horizontally growing underground stems (rhizomes), which is why the colonies are often an almost circular shape.
You can eat the leaves and they are quite tangy, however the leaves contain oxalic acid, which gives them their sharp flavour. Perfectly all right in small quantities, the leaves should not be eaten in large amounts since oxalic acid can bind up the body’s supply of calcium leading to nutritional deficiency. The quantity of oxalic acid will be reduced if the leaves are cooked. People with a tendency to rheumatism, arthritis, gout, kidney stones or hyperacidity should take especial caution if including this plant in their diet since it can aggravate their condition. The leaves will shut up shop ie close in on themselves when water is in short supply or in hot drying conditions or even during heavy (damaging) rainfall. Clever stuff.
As you can see from the close up photo below, the flowers are very delicate a beautiful with fine purple lines drawing your eye to a central orangey/yellow region. You might consider this is designed to attract pollinating insects and maybe it was once, but given that the process of pollination and fertilisation all takes place before the petals even open then this is not of importance. Perhaps it is just nature providing those of us who like wild flowers with a little gem to appreciate. Or as I now know they are insect pollinated at the beginning of the year and only self pollinating during the summer.