Piper species (Piperaceae) of Sri Lanka and the diversity of the economically important Piper nigrum (black pepper): An overview of what has been done and what is yet to be achieved
R. Samuel,
D. Yakandawala,
T. D. Silva,
S. Ranasinghe,
A. M. Wickramasuriya,
Y. Staedler,
O. Paun,
M. W. Chase
