PHYTOLITH ANALYSIS IN LEAVES OF EXTANT AND FOSSIL POPULATIONS OF NOTHOFAGUS SUBGENUS LOPHOZONIA

The phytolith morphology of leaves of all six extant species, one foss il species and a fossil population of an extant species of Nothofagus subgenus Lophozonia was examined to determine the utility of phytolith morphology for phylogenetic studies. One extant species of subgenus F uscospora (N. gunnii (Hook.f.) Oerst.) was included to allow a compari son between subgenera. Phytolith morphology and frequency in subgenus Lophozonia is quite similar among the extant evergreen species, and cl early distinguishes the evergreen from the deciduous species rather th an reflecting subgeneric differences. However, the deciduous species a re not particularly similar to one another, which may be due to their phylogenetic distance by comparison to the closely related evergreen s pecies. The Early-Middle Pleistocene population of Nothofagus cunningh amii (Hook.f.) Oerst. had well preserved phytoliths, which in morpholo gy and relative abundance were consistent with the extant species. How ever, the leaves of the Oligocene population of N. tasmanica R.S. Hill had poorly preserved phytoliths, which were relatively sparse and lac king in diversity. This is probably at least partly a result of taphon omic processes, but may also reflect phylogenetic differences.