Data from: Is sexual organ reciprocity related to legitimate pollen deposition in distylous Pulmonaria (Boraginaceae)?

Heterostyly, i.e. the reciprocal positioning of anthers and stigmas, is a
floral polymorphism that is thought to promote disassortative (i.e.
between-morph) pollination and to maintain genetic diversity within
populations. Recent research, however, has shown several cases of
heterostylous plant species in which the reciprocal positioning of the
sexual organs varies, which may affect the likelihood of ‘legitimate’
pollination between compatible morphs, and hence morph fitness and
ultimately the stability of this floral polymorphism. In this study, we
investigated floral morphology and stigmatic pollen deposition patterns in
nine Pulmonaria species (Boraginaceae) across Europe to test the
hypothesis that sexual organ reciprocity is related to legitimate pollen
deposition. We used a recently developed adaptive accuracy concept to
assess the level of reciprocity and to relate inaccuracies in positioning
of sexual organs to legitimate pollen deposition measured on stigmas in
the field. The nine investigated Pulmonaria species showed substantial
deviations from perfect reciprocity, with total inaccuracies varying
between 2.9 and 20.3% relative to the squared mean of all anther and
stigma heights in the population. In almost all cases, most of the
inaccuracy was generated by the high level organs. Total pollen deposition
was always higher on stigmas of long-styled individuals, but stigmas of
short-styled individuals received significantly more legitimate pollen
than stigmas of long-styled individuals (71.23% and 38.75% respectively).
We also found a weak, but significant relationship between measures of
inaccuracy and the level of disassortative pollination. Under these
conditions of pollen flow, the distylous mating system is predicted to
persist in only eleven (27%) of all sampled populations. Overall, these
results indicate that deviations from perfect reciprocal herkogamy are
common in Pulmonaria and have an impact on legitimate pollen deposition.