Floret Opening in Banksia menziesii R.Br.; The Importance of Nectarivorous Birds

Abstract

The rates and causes of floret opening in Banksia menziesii were examined in banksia woodland near Perth, Western Australia. On average, 40-60 florets opened per 24 h but this rate was highly variable over the flowering of individual inflorescences. The ages of inflorescences did not greatly influence the rate of floret opening, although fewer florets opened towards the end of flowering. Floret opening occurred predominantly during the day. The numbers of florets opening were similar in wet and dry weather conditions. Florets opened mainly in response to foraging by nectarivorous birds (Meliphagidae) but not honey bees. This would result in more effective pollen transfer to potential avian vectors which may enhance reproductive success.