3rd Annual Academic Symposium - Sandra Westergaard

Planchonella sandwicensis is a hypervariable Hawaiian endemic species. Previous authors have suggested the variation may be correlated to geography. In previous studies variation in size of leaves, but not shape, was studied across the archipelago. In the current study, standardized methods were used to quantify leaf shape of P. sandwicensis across its entire range. Five fully exposed leaves were collected and scanned from 39 trees across the islands of Kauai, Oahu, Molokai, Maui, and Hawaii. Leaf Analyser software was used to quantify the mean leaf shape for each individual. Principal Component (PC) analysis was used to detect the shape variation in co-ordinate models of the collected leaves. Size was analyzed separately from shape by using Procrustes fitting to scale the leaf models to equal size. Three PCs were calculated which correlated to width (PC1), symmetry (PC2), and apex and base angles (PC3). PC1 indicates that the leaf margin of specimens from Kauai are distinguishable from the other island populations. PC2 indicates specimens from Hawaii are less symmetrical than the other island populations. PC3 does not show any significant difference between island populations. PC1 on Kauai may be due to variation in just one tree. PC2 in Hawaii indicates a possible geographic correlation in the species. There is a small difference in the leaf shape of P. sandwicensis across the archipelago.