R.M. Dharmadasa^1,, P.L. Hettiarachchi², GAS Premakumara¹

Munronia pinnata (Wall) Theob. (Meliaceae) is a rare, therapeutically important medicinal plant widely used in traditional systems of medicine in Sri Lanka. Different populations of M. pinnata in Sri Lanka display an array of variable phenotypic characters. However, due to seasonal variations and rare flowering, study of reproductive characters in all populations is not possible. The present study emphasizes on the use of anatomical characters of leaf, stem and petiole of 13 populations of M. Pinnata as a systematic tool. Six monomorphic and 53 polymorphic quantitative and qualitative anatomical characters were scored. Cluster analysis was performed to derive the taxonomic relationship among the populations studied. A single access, indented key which could be used to identify anatomically different populations of M. pinnata was constructed using taxonomically stable anatomical characters. Populations collected from Ritigala reserve possessed distinguished characters such as presence of extra vascular bundles in outer part of the main vascular bundle in the midrib, higher number of epidermal cells in the upper epidermis, four separated parts in the stem vascular bundle and absence of secretory cells in the pith. Therefore, reconsideration of its taxonomic status is suggested. However, the level of taxon has to be decided after numerical analysis of combined taxonomic evidence of different disciplines. This study demonstrates that the importance of anatomical traits as an additional taxonomic tool for correct identification of M. pinnata.

anatomy, Munronia pinnata, Meliaceae, Medicinal plant, taxonomic tool