Taxonomic revision of the salwoods:: Acacia aulacocarpa Cunn. ex Benth. and its allies (Leguminosae: Mimosoideae: section Juliflorae)

A taxonomic revision of Acacia aulacocarpa Cunn. ex Benth. and its seven close relatives is presented. These species comprise the A. aulacocarpa group in the Acacia Mill. section Juliflorae and occur naturally in eastern and northern Australia, New Guinea and Wetar, eastern Indonesia. In the past, the name A. aulacocarpa has been widely misapplied. This species is relatively uncommon but has an extensive geographic range extending from the Atherton Tableland region in Queensland, south to northern New South Wales. Acacia aulacocarpa var. fruticosa C.T.White is considered conspecific with A. aulacocarpa. The name A. lamprocarpa O.Schwarz is reinstated for a northern Australian taxon that extends from western Queensland through Northern Territory to the Kimberley region of Western Australia. Five new taxa are described from A. aulacocarpa sens. lat., namely A. celsa Tindale (Queensland), A. disparrima subsp. disparrima M.W.McDonald & Maslin (northern New South Wales and Queensland), A. disparrima subsp. calidestris M.W.McDonald & Maslin (Queensland), A. midgleyi M.W.McDonald & Maslin (Queensland) and A. peregrina M.W.McDonald & Maslin (New Guinea). A full description is provided for A. crassicarpa Cunn. ex Benth. Mainly on the basis of their mode of pod dehiscence, two subgroups within the A. aulacocarpa group are defined: A. aulacocarpa, A. celsa and A. disparrima comprise the A. aulacocarpa subgroup and have pods that dehisce along the dorsal suture; and A. crassicarpa, A. lamprocarpa, A. midgleyi, A. peregrina and A. wetarensis comprise the A. crassicarpa subgroup and have pods that dehisce along the ventral suture. All species in the group, including the Indonesian species A. wetarensis, are illustrated and a key to the taxa is provided. Acacia celsa, A. crassicarpa, A. peregrina and A. midgleyi have considerable potential for wood production in tropical plantation forestry.