Asia in Australia: the forgotten flora of the Australian Wet Tropics

New discoveries by researchers at the University of Melbourne and James Cook University have helped uncover the ‘forgotten flora’ of Queensland’s Wet Tropics World Heritage Area.

Botanists David Meagher from the University of Melbourne and Andi Cairns of James Cook University have discovered a surprising number of Asian bryophytes – mosses, liverworts and hornworts – not found before in Australia.

One example is the moss Entodontopsis pygmaea, which had been previously observed in Vietnam, Thailand, China, India and Nepal, but which had never before been recorded in Australia, nor on any of the islands to the north and west of the continent. 

“Australian flora is often described as unique, the result of a long history of isolation and a northward-drifting and drying continent,” Mr Meagher says.

“The reality is very different, at least in the world of bryophytes.”

The genus Entodontopsis is new to Australia, as is another of the team’s moss discoveries, Clastobryophilum, which was found in a remote water catchment in the mountains near Tully, approximately 156 km south of Cairns.

In the rainforests of the Wet Tropics, it is now estimated that almost 50 per cent of native bryophyte species are also native to other countries, from Papua New Guinea north to China, west to the Indian subcontinent, and east to the islands of Polynesia.

Mr Meagher says exactly how the Asian species reached Australia, or vice versa, is still a matter of conjecture.

“Birds are potential long-range dispersers of bryophytes. Many species use the soft plants for nesting material and can ingest them or get them caught in feathers or on muddy feet,” he says.

“But cyclones might be the main distributors of bryophytes in the tropics because they can strip vegetation and carry fragments vast distances.”

Research at James Cook University has also shown that bryophytes can pass unharmed through the gut of flying-foxes, which can migrate very long distances in the tropics. 

Both researchers describe the bryophyte flora of tropical Australia as ‘forgotten flora’. 

“Many species have never been properly described or illustrated, and some we found had not been seen for more than a century,” Mr Meagher says.

“They are difficult to identify because the literature on them is mostly scattered in dozens of botanical journals, and for this reason alone they are not included in large-scale biodiversity studies.

“To correct this imbalance, we are continuing to document bryophytes in tropical Australia in preparation for the publication of a field guide and online key.”

Descriptions of Entodontopsis and Clastobryophilum were published in Volume 17 of the open-access journal Telopea. Sixteen other species not found previously in the Wet Tropics, as well as nine species new to science, have been published in the journal Nova Hedwigia, and several other papers are in preparation.

www.botany.unimelb.edu.au