LEAF ARCHITECTURE OF SOUTH-AMERICAN NOTHOFAGUS (NOTHOFAGACEAE) USING TRADITIONAL AND NEW METHODS IN MORPHOMETRICS

Leaf morphology has been the subject of several studies in Nothofagus especially in the context of the taxonomy and evolutionary relationshi ps of taxa within the genus, which are still controversial. The leaf a rchitecture of N. dombeyi, N. betuloides and N. nitida, dominant trees of temperate forest in southern South America, is compared using vena tion patterns, landmarks, and entire outlines. In terms of venation pa tterns N. dombeyi and N. betuloides were more similar to each other th an to N. nitida. Similar results were Found when differences in shape were analysed by discriminant analyses of shape coordinates (landmarks ) and Fourier coefficients (outlines). For both analyses, the first di scriminant function separated N. nitida from the other two species; th ese were also distinguished but showed greater overlap with each other . This study, in conceit with information from allozyme data confirms the hypothesis of a more ancestral position for N. nitida with N. domb eyi and N. betuloides being more recently derived. In addition to diff erences in shape, the size component of leaf morphology indicated that whereas N. betuloides had the smallest leaves, N. dombeyi spanned the greatest range and has the biggest leaves. Given that the data shown here were obtained from seedlings grown under common-garden conditions , differences in both shape and size, seem to be important components of leaf morphology that may warrant consideration in characterizing th ese and other species of Nothofagus. (C) 1996 The Linnean Society of L ondon