Abstract
Brachychiton sp. ormeau is an endangered rainforest tree endemic to Ormeau in South-East Queensland. Recognised as a distinct new species, it is thought to be only recently evolved. B. sp. ormeau exists in a critically small population within a restricted geographic range, however B. rupestris, the most taxonomically similar species in the genus, is significantly more widespread and is known to hybridise easily. This study aims to assess levels of genetic variation within and between all known populations and sub-populations of B. sp. ormeau, as well as comparing it with levels of variation within nearby populations of B. rupestris and a hybrid swarm (B. rupestris × B. populneus). Chromosome numbers of all three species will be compared and GIS techniques will be used to compare current species distribution with preclearing land data. This will provide valuable data on the amount of genetic variation within B. sp. ormeau and how it is distributed, the likelihood of its evolution through polyploidy or hybridisation, and whether it may be restricted due to past land clearing and fragmentation. Results of this study will guide potential species recovery that might utilise translocation or population enhancement, or establishment of new populations elsewhere through restoration planting.