Three wildflowers I'm seeing a lot of at the moment colonising neglected areas, particularly along railway lines which are useful corridors for nature.
 Ox-eye Daisies which were once called Moon Daisies (Leucanthemum vulgare) grow in great luminous drifts. They're leggy but sturdy and rise up from the surrounding greenery in sunny spots.
  The bright yellow flowers of Ragwort (Senecio squalidus) have become more and more common over the years. It is sometimes referred to as Oxford Ragwort having been introduced to the Oxford Botanic Gardens around 1690 from its native habitat on the slopes of Mount Etna in Sicily.
 An account circa 1794 describes that by then it had become "very plentiful on almost every wall in Oxford". The gravel and clinker of railway tracks proved to be a reminder of home and it went to on to be spread ever wider by the rail network.
 Red Valerian (Centranthus ruber) also hails from the Mediterranean; introduced as garden plant it soon jumped the fence. Old walls and the aforementioned clinker suit it. Generally it is indeed red but as the photograph shows there is a less common white form (C. albus) and this crosses to make a pinkish variety where they grow in proximity.