Portulaca oleracea
The Bramble Cay melomys was described in 2002 as Australia's most isolated mammal. The cay is located in the northeastern portion of the Torres Strait, approximately from the mouth of the Fly River in Papua New Guinea. The cay is between , but the rodent only occupied the vegetated portion of the island, measuring approximately . The vegetation of the island comprises grasses and herbs, generally shorter than . 11 species of plants have been recorded on the island; the common ones include "Portulaca oleracea", "Boerhavia albiflora", "Cenchrus echinatus", and "Amaranthus viridis". The island was also characterised by large populations of seabirds, as well as ecological disturbance caused by annual green turtle breeding. The Bramble Cay melomys preferred the more densely vegetated areas, and avoided those parts of the island that had high densities of seabirds. The species was observed to feed on "P. oleracea" as well as on turtle eggs. The breeding season of the species was lengthy, and the sex ratio was skewed towards females.