Systematics of genus Garcinia L. (Clusiaceae) in Sri Lanka: new insights from vegetative morphology

The genus Garcinia L. (Family: Clusiaceae) is represented by ten species in Sri Lanka including five endemic species. Systematics of the genus hitherto were primarily based on reproductive morphology. A recent study was carried out in order to evaluate the species limits of Sri Lankan Garcinia using anatomical characters. However, the field identification of Garcinia is challenging due to the presence of unisexual flowers, strict seasonality in flowering and fruiting, and failure to use anatomical characters.

The aim of this study was to investigate the relationships among the species and to construct an identification key based on the vegetative morphological characters. Specimens of all representative taxa were sampled from different geographical locations. A total of 97 specimens were collected and similarity and cladistic analyses were performed based on 47 vegetative morphological characters. The results suggest that the sampled species fall into two major groups characterized by leaf morphological features. Major groups can be further divided into subgroups by bark colour and tertiary venation. The overall results demonstrate within species variations of G. hermonii and G. terpnophylla highlighting the presence of different varieties. The dichotomous key constructed using conspicuous vegetative characters will be a valuable tool for identification of Sri Lankan Garcinia species in the field. The relationships found in this study provide insights to the phylogeny of the species. The results are congruent with those of the recent anatomical study and revealed the importance of combined multidisciplinary data analysis to elucidate more robust species relationships.

Keywords: Bootstrap, cladistic, Garcinia, phylogeny, strict consensus tree, vegetative morphology

doi :10.4038/jnsfsr.v38i1.1723

J.Natn.Sci.Foundation Sri Lanka 2010 38 (1):29-44