As a first step to evaluating the role of adaptive variation of functional traits in the radiation of the Hawaiian silversword alliance (HSA) we will correlate functional traits with environmental parameters across the full phylogenetic span of the HSA. We propose to measure anatomical and morphological traits relating to hydraulic capacity and drought tolerance (Carlquist 2003; Sperry 2003), as well as leaf level isotopic measurements to quantify the efficiency of carbon uptake versus water-use efficiency (WUE). Functional traits will be related to environmental data using phylogenetically independent contrasts to test the hypothesis that evolutionary change in functional traits has been associated with changes in environments occupied by each lineage.

• Carlquist, S. 2003. Wood anatomy of Madiinae in relation to ecological diversification. Pp. 129-144 in S. Carlquist, B. G. Baldwin and G. D. Carr, eds. Tarweeds and silversowrds: evolution of the Madiinae (Asteraceae). Missouri Botanical Gardens, St Louis.
• Sperry, J. S. 2003. Evolution of water transport and xylem structure. International Journal of Plant Sciences 164:S115-S127.