The monotypic tropical tree species Hagenia abyssinica (Rosaceae) is an anemogamous and anemochorous broad-leaved dioecious tree species native to Africa. Fossil pollen evidence suggests that it immigrated into Ethiopia from the south during the late Pleistocene. The chloroplast haplotypes identified in Hagenia are grouped into two lineages and demonstrated a strong pattern of congruence between their geographical distribution and genealogical relationships. Restricted gene flow through seeds, contiguous range expansion, mutation and rare long-distance dispersal shaped the genetic structure in the...