Floral traits of Belgian Ericaceae species: Are they good indicators to assess the breeding systems

A variety of floral traits likely to be associated with the reproductive system of seven Belgian Ericaceae species (four Vaccinium species : V myrtillus, V oxycoccos, V uliginosum and V vitis-idaea, as well as Andromeda polifolia, Calluna vulgaris and Erica tetralix) were quantified. These traits included the size of the flower, the number of pollen tetrads and ovules, the distance between the stigma and the anthers, and the exsertion of the style. Pollen-ovule ratios suggested a more or less mixed mating system in all species. Floral traits (greater pollen-ovule ratio, style highly exserted, higher stigma-anther distance) in V vitis-idaea suggested that it functioned more as an outcrosser than its congeners. On the opposite, floral traits suggested that E. tetralix and V uliginosum appeared to be more selfing than the other species.