Assembly of fairy circles in the Namib from genetically distinct, non-clonal plants at different ploidy levels

Fairy circles are fascinating large-scale vegetation patterns . Each individual circle is typically made up of perennial tufts of Stipagrostis grass growing around a barren central patch roughly two to ten meters wide, with annual grasses in the matrix . The circles often show a regular hexagonal arrangement over larger areas. Fairy circles have been found in very arid grasslands in Southern Africa, e.g. in Namibia, in Australia and Israe. The processes leading to their formation continue to be the subject of an intense debate. One hypothesis posits that they arise from the vegetative growth pattern of grasses. As a result, fairy circles would be clonal. We have tested this hypothesis using multi-locus genotyping of samples from multiple fairy circles formed by two different Stipagrostis species. Our results clearly show that fairy circles are not clonal, refuting the vegetative-growth hypothesis. Rather, they are formed by genetically distinct individuals via an alternative process.