Can and do ericas self pollinate

Abstract 

Within the Cape Floristic Region many lineages are characterised by large floral 

diversity. The genus Erica is one of these lineages, making up -7% of the CFR. 

Surprisingly, even though pollinators have been suggested to be a driving force of floral 

morphology, the role of pollinators in the floral diversification and speciation of this 

genus is not yet well understood. Therefore the aim of this paper was to establish if 

Erica species can and do self-pollinate. Two Erica species, E. plukenetii and E. urna

viridis, were obtained from Kirstenbosch nursery, where hand-pollinations were 

performed on 15-20 flowers of each of three treatments (self-pollination, cross

pollination and autogamous self-pollination. Additionally pollen tube analyses were 

performed on seven Erica species, which were collected from the Constantia Mountain. 

In E. plukenetii, self-incompatibility seems to be the predominant breeding system. It 

appears that, like E. urna-viridis, most of the other species analysed, via pollen tube 

analyses, have the potential to self-pollinate. However, more experiments are required 

to establish if these species are truly self-compatible. Autogamy, on the other hand, does 

not appear to set seed in the species studied. Therefore it would be fair to say that some 

ericas can self-pollinate but none actually do self-pollinate. These results indicate that 

ericas have a strong dependence on pollinators for seed set and in the past speciation 

may have occurred due to adaptation to different pollinators, when opllinators were 

scarce. 

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