ON THE DISTRIBUTION OF IRIS GERMANICA L.

Abstract

In the course of a wider study of the species, it has been found that many of the forms of I. germanica L. previously assumed to be near-sterile clones are, in fact, groups of more or less closely related plants, appearing similar only in a very superficial sense and often much more fertile than has been realised. Apart from the blurring effects of its widespread use as a cultivated decorative plant, I. germanica on examination in its naturalized habitats and in old established cultivations in France and Spain has proved to consist, predominantly or solely of one or another of these groups of closely similar variants, often over an extended range. From observation it appears that a similar pattern, with one group dominating an often large region - perhaps hundreds of kilometres square - to vanish entirely in an adjoining area, replaced by another group, totally distinct in vegetative and flora characteristics, is likely to be continued throughout southern Europe and western Asia. The situation is complicated though by pronounced genetic instability in at least some groups.