Australia's lonely boab (Adansonia gregorii)
Australia has one endemic species of boab occurring in the north-western monsoonal tropics, all other species being found only in east Africa and Madagascar. This unusual biogeographic pattern has never been adequately explained. Like the African and Madagascan species, Adansonia gregorii flowers at night during the rainy season, and is pollinated by bats. During a recent field expedition to Western Australia's remote Kimberley region, two colleagues and I were thrilled to find a boab with buds remaining - field work access in the Kimberley is difficult except in the dry season when most boabs have neither leaves nor flowers. A long drive to the tree at night from our camp - stopping along the way for tiny rock wallabies and frogmouths - failed to find any open flowers! However, a few weeks later in the main street of Broome, another tree had buds and this open flower. With extra water from adjacent gardens and lawns, these trees were flowering unusually late in the season. Photographing a boab in flower was a bucket-list item for me - tick!