Pollination of the red-hot poker Kniphofia laxiflora (Asphodelaceae) by sunbirds

Abstract

Most of the species in the large African genus Kniphofia have floral traits that conform to the bird pollination syndrome, however there has been very little empirical work to confirm that birds are effective pollinators of Kniphofia species. From selective exclusion experiments, behavioural observations and pollen load analyses, we identified Amethyst Sunbirds ( Chalcomitra amethystina) and Malachite Sunbirds ( Nectarinia famosa) as the primary pollinators in two populations of Kniphofia laxiflora, with bees playing a smaller role. Bird visitors obtain moderate volumes (∼ 9 µl) of relatively concentrated (∼ 15%) hexose-rich nectar in the flowers. This species is shown to be genetically self-incompatible, and thus reliant on pollinator visits for seed set. Although mountain pride butterflies ( Aeropetes tulbaghia) have been identified as important pollinators of this species at two other populations, they did not occur at the two populations we studied.