Hurray! Spring is definitely here with the flowering of Lesser Celendine Ranunculus ficaria and Wood Anemone Anemone nemorosa, both members of the Ranunculaceae or Buttercup family.
As usual my ignorance was highlighted after looking at these plants in detail. The Lesser Celendine petals seemed almost to have an extra spray-on layer of shiny yellow on their upper surface and a tiny lobed appendage at the base of each petal (is this the nectar pit?). The leaves (especially the smaller ones) also had a purple tinged line around their edge with a very thin translucent margin outside of this. Interestingly they occur in the shaded areas along hedge-banks and the like but also can be found in the shingle banks of the river which are seasonally inundated with water alongside Coltsfoot Tussilago farfara. Rose says the petals are up to 15 mm but mine were often 20 mm and according to Stace there are a number of sub species, as well as garden escapes, so further investigation will be required.
A nemorosa was growing alongside the river on a grassy bank. Interestingly according to Rose its supposed to be hairless and Streeter says its glabrous to sparsely hairy but mine is I would say conspicuously hairy (Poland and Clement describe it as having hairy basal leaves and petiole). The flower stalk and the bracts have very long apparently unicellular hairs both on the edges of the bracts but also on the leaf veins on the upper surface and all over the lower surface. (From what I have seen of other photos on the internet this seems to be quite common). The underside of the white sepals also had sparse translucent hairs along their mid rib.