White and yellow flowers are the colours of spring.
‘White flowers (which reflect all types of light) may be distinguishable to bees depending on the amount of ultra-violet they reflect, while yellow flowers may appear simply yellow (e.g.cowslip) or ‘bee-purple’ (creeping cinquefoil)because the latter also reflects ultra-violet.’ … Almost certainly these responses of pollinators to flower colours explain the obvious …of different colours at different times of year. In early spring white is commonest… at a time when few pollinators. and those mainly flies, are to be found’ (Fitter pp 278-9)
I think woodlands are a good place to start studying plants because there are just a few easily recognisable flowers forming distinctive stands. For example in this wood near Abergavenny, South Wales, the ground is literally covered in Wood Anemone Anemone nemorosa.
Apparently A nemorosa can form large clonal patches that may survive for hundreds of years, however
‘Development of the seedling and young plant is very slow, and individuals may not flower until 10 years old…The seed is not dispersed far from the parent plant. A maximum of 130mm has been reported in one population..Thus a.n. has a low colonizing ability and is most typically associated with older areas of woodland or grassland.’ (Grime et al p83)
Also lining the streams running through the wood are these brilliant yellow King-cups Caltha palustris.
This is another long lived species which forms distinct stands with individual plants living up to 50 years (Grime at al p126).
Here and there are a small number of Lesser Celandines Ranunculus ficaria. Like A nemorosa this plant persists with numerous root tubers that spread and can cover considerable areas.
Interestingly all the above species are members of the same family, the Ranunculaceae and at this time of year they are totally dominating the ground layer. Occasionally however the Brassicaceae is represented by Cuckoo Flower Cardamine pratensis
Another white flower (that is not that common in this wood) is Wood Sorrel Oxalis acetosella (Oxalidaceae)
‘The species is suppressed by heavy depositions of deciduous tree litter, and for this reason is often restricted to raised areas on the woodland floor such as tree bases and small hummocks’ (Grime et al p424)
Last but by no means least an unusual plant that is not yet in flower (but is neither white nor yellow!), Herb Paris Paris quadrifolia, yet another clonal long lived plant but this one is more or less restricted to woodland..