Whitlowgrass (Erophila verna) agg is a white flowering crucifer with deeply notched petals. The above plants are very small. It is among a group of very similar subspecies. I first came across this plant in 1980 growing between the railway sleepers near the now demolished coal plant at Widdrington colliery. The railway track was destroyed with the coal plant and was swallowed up by the Steadsburn opencast in 2009. Another colony still exists in the railway sidings at Felton lane opposite Colliersdean wood.
In Morpeth Whitlowgrass used to thrive on the edge of a car park near the old bus station in Stanley terrace but this site was destroyed during the development of Sanderson arcade shopping centre a couple of years ago. The above pics were taken at Morpeth railway station growing in the mossy gaps between the cobbled edge of the car park at the rear of the station (opposite Greens agriculture store).