K. A. R. S Perera
Department of Botany, University of Kelaniya, Kelaniya, Sri Lanka
The Open University of Sri Lanka, Nawala, Nugegoda, Sri Lanka
M. D. Amarasinghe
Department of Botany, University of Kelaniya, Kelaniya, Sri Lanka
S. Somaratna
The Open University of Sri Lanka, Nawala, Nugegoda, Sri Lanka