¾-power scaling between metabolic rate and body mass is regarded as near-universal across organisms. However, there are compelling reasons to question ¾-power scaling in woody plants, where metabolic rate≈leaf area. This leaf area must provide carbon to the metabolically active sapwood volume (V _MASW). V _MASW is necessarily a much smaller volume than total wood volume, meaning that scaling of total leaf area LA _tot with V _MASW should be >¾. Within populations of a species, variants in which V _MASW increases per unit leaf area with height growth (e.g. ¾ scaling) would have proportionally less carbon for growth and reproduction as they grow taller. Therefore, selection should favor individuals in which, as they grow taller, leaf area scales isometrically with V _MASW. Using tetrazolium staining, we measured total V _MASW and total leaf area across 22 individuals of Ricinus communis and confirmed that leaf area scales isometrically with V _MASW, and that V _MASW is much smaller than total sapwood volume. _. With the potential of the LA _tot-V _MASW relationship to shape factors as diverse as the crown area-stem diameter relationship, conduit diameter scaling, reproductive output, and drought-induced mortality, our work suggests that the notion that sapwood increases per unit leaf area with height growth requires revision.