Convergent Floral Evolution in South African and Australian Proteaceae and Its Possible Bearing on Pollination by Nonflying Mammals

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Abstract
Striking convergent evolution for a hidden (cryptic), ground flowering (geoflorous) habit in distantly related, low shrubby Australian and South African Proteaceae is interpreted as an adaptation for pollination by nonflying mammals. The cryptic, geoflorous habit is especially well developed in species groups of Dryandra in southwestern Australia and Protea in the Cape region of South Africa. Considerable circumstantial evidence exists in both regions for pollination by mouselike, often arboreal marsupials in Dryandra and true rodents in Protea. Evidence from inflorescence structure suggests the cryptic, geoflorous habit is derived from bird-pollinated species, possibly in response to fires common in the sclerophyllous communities where these genera grow. A number of floral characteristics and the occurrence in Australia of mouselike marsupials adapted to a nectar (and pollen?) diet suggests that a class of flowers has evolved for pollination by nonflying mammals. This postulated floral class possibly also extends to other Australian arboreal proteaceous and also myrtaceous genera, but in South Africa is probably restricted to Protea.