Mount Tomah Botanic Garden

The Supercontinent

Early explorers were puzzled to find that not only was the flora of the southern hemisphere substantially different from that of the northern, but that there was a clear relationship between the floras of areas as far apart as South Africa, Australia, New Zealand and southern South America.

This was eventually explained by the recognition that the southern land masses once were joined in the supercontinent of Gondwana. Many of the plant groups which now dominate the southern hemisphere floras, for example the Proteaceae and Myrtaceae, are believed to have had their origins in Gondwana before it began to break up about 120 million years ago, leaving the plants of the various continents and islands to evolve their present distinctive characters in isolation. Modern members of these Gondwanan families have now been brought together in the plantings at Mount Tomah.

Fuchsia procumbens, a species from New Zealand

South African members of the Proteaceae in the Rock Garden

The principal areas in which these species have been planted are the entrance drive, the adjacent Gondwana Woodland and Gondwana Walk, the planting of Proteaceae immediately to the east of the Visitor Centre, the Rock Garden, and the Southern Hemisphere Woodland which has been planted below it.

The southern beeches (Nothofagus spp.), which have been planted along the entrance drive and which occur in New Guinea, Australia, New Caledonia, New Zealand, and South America, exhibit a typical Gondwanan distribution.

Likewise, members of the conifer families Podocarpaceae and Araucariaceae, which includes the newly-discovered Wollemi Pine (Wollemia nobilis), are widely distributed in the southern hemisphere. Similarly, members of the Proteaceae are found from southern Africa east across to South America. Members of all these and other Gondwanan families are well represented in the Garden.

Nothofagus moorei, a southern beech from eastern Australia