Pattern analyses of density and performance data collected from separate populations of Atriplex inflata in the western Riverine Plain of New South Wales consistentiy indicated two linear scales of contagion at 2-4 and 16 m. The largerscale plant pattern corresponds to a similar pattern of microtopographical variation but regressions of density alone on microtopography are significant, indicating possible alternative mechanisms for establishment (as indicated by density data) and subsequent performance (as indicated by cover data). The performance of A. inflata plants has been assessed experimentally on a range of natural soils and in controlled nutrient solution culture. The results suggest that performance (as estimated by dry weight yield) is significantly affected by soil type, water stress, and a soil type ° water stress interaction. The prime effect of soil variation on yield appears to be mediated by variation in soil cation balance.