Genetic and morphological differentiation across a contact zone between two postglacial immigration lineages of Helianthemum nummularium (Cistaceae) in southern Scandinavia
Helianthemum nummularium (L.) Mill. has two subspecies in southern Scandinavia, which differ in an indumentum character that is inherited as a Mendelian gene with two alleles. The dominant allele is the genetic basis for the key character of subsp. obscurum (absence of a dense felt of stellate hairs on the abaxial surface of the leaf), whereas the recessive allele is the genetic basis for the key