The keel petal colour polymorphism of Lotus corniculatus L. in Scotland

In a survey of the keel petal colour polymorphism in Lotus corniculatus L. conducted at 61 coastal and inland locations in Scotland, there was a major difference in morph frequency between populations in the west and those in the east and central areas, with the dark keel being at low-relative frequency at most western locations. When figures for east and central Scotland were considered, there was a slight but statistically significant increase in the dark keel morph with increasing latitude, a pattern which was not found in Scotland as a whole.