The basic material of this study was two collections of Festuca rubra from the local hills. The one collection was of 1481 plants all gathered from within a 100 square-yard quadrat; the other of 340 plants was of wider distribution.
Detailed morphological examination of the material growing as spaced plants suggested that relatively few genotypes were present. Further work, involving a replicated field trial and an investigation of self-and cross-incompatibility corroborates this view. One of the genotypes occurs abundantly within an area of more than 240 yards diameter.
Among the genotypes there were considerable differences of colony size and density. There were also indications of differences in ecological requirements.
In the field trials there is no indication that plant characters within a clone are in any way affected by the environment from which the material was gathered.
A consideration of the presumed age of the genotypes and the vigour of their vegetative spread suggests that very little ecotypic differentiation can be taking place in F. rubra at the present time. Any observable differentiation must have taken place either before colonization or during its early stages.