While we were driving on the motorway this weekend I noticed patches of pale pink flowers along the verge and also in the central reservation. The plant is Danish Scurvy Grass and it flowers from February to June. I don't have any photographs (obviously as it was growing in the middle of a busy motorway!) but I found some pictures here. It gets its name because the leaves contain high levels of vitamin C and in the past it was eaten to prevent scurvy.
Its natural habitat is in coastal areas where it can withstand the salty windy environment. Until fairly recently it was rarely found inland although it was occasionally spread along railway lines as the ballast that supported the sleepers often came from the coast and seeds were carried along with it.
Over the last twenty years or so it has colonised the centre of motorways as they provide a suitable environment for growth. Salting the roads in the winter leads to a build up of salt in the soil which makes it unsuitable for some inland plants but perfect for a plant adapted to coastal conditions. It is thought that a few plants grew on the verges of roads near the coast and then the winds and turbulence created by passing traffic dispersed the seeds along the motorway corridor.
I think it is amazing how this little plant has spread throughout the country in such a short time taking advantage of new environments with the right conditions for growth. What a plucky little plant, it looks so delicate yet it thrives in really harsh situations and what a good example of how to make the most of changing environmental conditions.