Phenotypic variation of leaves and stems of wild stands of Cordyline australis (Lomandraceae)

To determine whether there are geographical patterns in the phenotypic vari ation of wild populations of Cordyline australis (ti kouka, cabbage tree), stem size, and leaf size and shape were recorded for populations at 29 loca tions in New Zealand ranging from latitudes 34 degrees 37' to 46 degrees 07 'S and altitudes from 1 to 425 m. Correlations between stem and leaf variat ion and site and stand characteristics were examined. Stem diameter increas ed with increasing latitude and altitude. Leaf size dimensions and leaf sha pe ratios that defined differentiation of the petiole, and of leaf blade ta per, also showed variation related to latitude. The phenotypic variation wa s predominantly continuous and followed environmental gradients that could have induced it. There was some local and regional discontinuity of phenoty pic variation that was most apparent for stands in central-eastern North Is land.