The American Proteaceae

Abstract

The American Proteaceae are outliers from the main centres of diversity of the family in Australia and South Africa. There are about 83 species in eight genera which all belong to the monophyletic subfamily Grevilleoideae. Three genera, Embothrium, Oreocallis and Lomatia, are placed in the tribe Embothrieae (sensu Johnson and Briggs), four Euplassa, Gevuina, Panopsis and Roupala in the Macadamieae and the single genus Orites in the Oriteae. There are five genera endemic to America and three also have species in Australia and New Guinea (Gevuina, Lomatia and Orites). The Proteaceae appear to have arrived in South America via two routes. The larger genera Euplassa, Panopsis and Roupala, which are all endemic to America and have a general distribution in northern South America and south-eastern Brazil, are derived from Gondwanaland before it separated from South America. The remaining genera are distributed either in temperate South America or in the high Andes and appear to have arrived more recently via the Australia–Antarctica–South American connection. Three of these genera have species in both regions. The centres of species diversity of Euplassa, Panopsis and Roupala fall outside hypothesised forest refugia, indicating that they are not true rainforest species but species of seasonal habitats like those achieved at higher altitudes where they are commonly found. Two genera,Panopsis and Roupala, have reached Central America after the central American land bridge was formed six million years ago. The exact relationship to genera on other continents is still unclear and there is a need for a cladistic biogeographic analysis of the group based on both morphological and molecular data.

Mixed hummingbird: Long‐proboscid‐fly pollination in ‘ornithophilous’Embothrium coccineum (Proteaceae) along a rainfall gradient in Patagonia, Argentina

“…This suggests that in the temperate forests of southern South America, hummingbirds and tanglewing flies likely constitute a true 'functional group' of pollinators (sensu Fenster et al 2004) that would be exerting a coincident selective pressure, at least concerning nectar sugar concentration. In fact, the historical coexistence of tanglewing flies, which differentiated in South America through the Cretaceous period (Bernardi 1973), with Embothrium, which is present in South America at least since the Oligocene (Dusén 1899;Prance & Plana 1998), and the much later appearance of hummingbirds in the early Miocene in Andean Patagonia (Bleiweiss 1998) suggest that ornithophily in E. coccineum may be a recent acquisition. The ancestral condition was probably pollination by Nemestrinidae (but see Aizen & Ezcurra 1998).…”

Co-occurrence of Proteaceae, laterite and related oligotrophic soils: coincidental associations or causative inter-relationships?

“…Lomatia, Gevuina and Orites) have representatives in Australia. The genus Roupala, with close to 60 species, provides a case of prolific speciation across a wide range of mostly tropical habitats (Prance and Plana 1998). In most South American ecosystems, proteaceous elements tend to be at lower relative density than in the Cape region of South Africa or south-western Western Australia.…”

“…The resource of living Proteaceae in South America (Table 1) has been recently reviewed by Prance and Plana (1998) who regard the species and genera (all Grevilleoideae) concerned as 'outliers' of Australasian and African centres of diversity. Distribution of species and genera shows that most taxa occur in highland seasonal environments rather than lowland rainforest regions.…”

A smaller Macadamia from a more vagile tribe: inference of phylogenetic relationships, divergence times, and diaspore evolution in Macadamia and relatives (tribe Macadamieae; Proteaceae)

“…93 million years before present [Ma BP]; Dettmann and Jarzen, 1998), prior to most fragmentation events in the southern supercontinent Gondwana. The family's far‐flung distribution in the southern hemisphere is generally explained by the rafting of ancestors on those fragments (e.g., Venkata Rao, 1971; Johnson and Briggs, 1975; Weston and Crisp, 1994, 1996; Prance and Plana, 1998; Prance et al, 2007; cf. Barker et al, 2007), as is the distribution of many other organisms (reviewed in Sanmartín and Ronquist, 2004).…”

“…If the tribe and the landmasses that it occupies did indeed “co‐speciate” (as in the vicariance framework commonly accepted for the family) and the habitats and suite of available dispersers on the daughter landmasses are analogous, then we would expect that evolution in the tribe's diaspores will be uncorrelated with the disjunctions. The genera of tribe Macadamieae produce early or tardily dehiscent fruits (dehiscing at fruit maturity or seed germination, respectively) that are mostly >1 cm in size (Filla, 1926; Sleumer, 1955a; Virot, 1968; Venkata Rao, 1971; Johnson and Briggs, 1975; Weston, 1995a–1995d; Weston and Crisp, 1996; Prance and Plana, 1998; Qiu and Weston, 2003; Prance et al, 2007; Fig. 1).…”