PATTERNS OF MORPHOLOGICAL VARIATION WITHIN ACACIA SUAVEOLENS (MIMOSACEAE)

Acacia suaveolens shows a considerable degree of morphological variabi lity throughout its range in eastern Australia. Multivariate morphomet ric analyses of data from 375 herbarium specimens suggest that there a re five polythetically distinct forms within this species. The morphol ogical boundaries between these forms are somewhat arbitrary but are c losely related to a number of environmental variables. Discrimination between these forms is possible only on the basis of a combination of attributes. In all cases, the distinctions between the forms are maint ained in offspring plants grown under controlled environmental conditi ons, indicating that these morphological differences are genetically f ixed. These forms are taxonomically treated as new subspecies. Apart f rom the typical form (subsp. suaveolens), which is widespread, the fol lowing morphological forms have been identified: a form with narrower phyllodes, restricted to the Holocene sand dunes in the Myall Lakes re gion (subsp. myallensis D. Morrison & A.J. Rupp); a form with wider ph yllodes and longer pulvinus, and longer and thicker seeds, occurring i n areas with an altitude above 300 m (subsp, montana D. Morrison & A.J . Rupp); a form with wider phyllodes, more flower heads per raceme, th icker seeds, and a small rootstock, restricted to the Grampians region (subsp. grampianensis D. Morrison & A.J. Rupp); and a form with short er phyllodes, shorter internodes, shorter fruits, thicker seeds and a prostrate habit, occurring on windswept coastal headlands (subsp. pros trata D. Morrison & A.J. Rupp).