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

Abstract

A taxonomic revision of Acacia aulacocarpa Cunn. exBenth. and its seven close relatives is presented. These species comprise theA. aulacocarpa group in the AcaciaMill. section Juliflorae and occur naturally in eastern and northernAustralia, New Guinea and Wetar, eastern Indonesia. In the past, the nameA. aulacocarpa has been widely misapplied. This speciesis relatively uncommon but has an extensive geographic range extending fromthe Atherton Tableland region in Queensland, south to northern New SouthWales. Acacia aulacocarpa var.fruticosa C.T.White is considered conspecific withA. aulacocarpa. The nameA. lamprocarpa O.Schwarz is reinstated for a northernAustralian taxon that extends from western Queensland through NorthernTerritory to the Kimberley region of Western Australia. Five new taxa aredescribed from A. aulacocarpa sens. lat., namelyA. celsa Tindale (Queensland),A. disparrima subsp. disparrimaM.W.McDonald & Maslin (northern New South Wales and Queensland),A. disparrima subsp. calidestrisM.W.McDonald & Maslin (Queensland), A. midgleyiM.W.McDonald & Maslin (Queensland) andA. 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 subgroupswithin the A. aulacocarpa group are defined:A. aulacocarpa, A. celsa andA. disparrima comprise theA. aulacocarpa subgroup and have pods that dehisce alongthe dorsal suture; and A. crassicarpa,A. lamprocarpa, A. midgleyi,A. peregrina and A. wetarensiscomprise the A. crassicarpa subgroup and have pods thatdehisce along the ventral suture. All species in the group, including theIndonesian species A. wetarensis, are illustrated and akey to the taxa is provided. Acacia celsa,A. crassicarpa, A. peregrina andA. midgleyi have considerable potential for wood production in tropical plantation forestry.