Ligustrum (Oleaceae) in Southern India

Abstract

Summary. A critical review of the material in the Kew Herbarium of Ligustrum from the Western Ghats, including some recent collections, has led to the conclusion that only one species, L. perrottetii A.DC., should be recognized, although one or two aberrant forms need to be studied in the field. The presentation to Kew of several recently collected specimens of Ligustrum from the Palni Hills by Dr K. M. Matthew of the Rapinat Herbarium, Tiruchirapalli, Tamil Nadu, has led to a review of the genus in southern India. This has revealed that within the limited range of characters available, the members of this genus from this area are found to be particularly variable, and do not form discrete entities which may be recognized taxonomically. In fact, there appears to be only one variable species. In the past various botanists have attempted to separate species and varieties on, for example, density and pubescence of the inflorescence or the size, texture and shape of the leaves, but the groups that have been recognized are not clearcut. This lack of discrete taxa is borne out by the impossibility of devising a workable identification key to those that have been recognized in the past. The problems in this group are also reflected in the extensive synonymy, which has been complicated by authors' frequent modification of the previously used names by such phrases as 'sensu' and 'pro parte'. Furthermore, Dr Matthew informs me that in the field there appear to be no ecological reasons for this variability, nor do there seem to be characters, not apparent from dried specimens, such as those of habit etc., which might be helpful taxonomically. However, a more detailed study, based on the observation of living populations, might perhaps reveal a pattern in the variation not discernible with the material at present available.