A fine patch of Winter Aconites (Eranthis hyemalis) bathing in the sun on a bank in the village of Charlton in Hertfordshire. One of the earliest flowering spring bulbs they are from southern Europe originally but have naturalised in parts of the UK. They escape from gardens and go native, which is probably the case here.
 Having said that I haven't found them to be particularly suited to growing in London. I think the clay soil is too dense for them. In lighter soils the stems unfurl out of the loose earth and the dainty flowerheads nod up to the sky, opening when the sun is on them.
 I've walked from nearby Hitchin to Charlton many times. If only the village pub hadn't closed down last year- it's directly opposite the Aconites and I could have had a pint while I gazed out at them.