Materials used in this study were collected in Sri Lanka andIndia (Table 1). Vouchers are housed in the herbarium of theUniversity of Tokyo (TI). For anatomical observation, materialswere fixed with FAA (formalin : acetic acid : 50% ethyl alcohol; 5 : 5 : 90 v/v), dehydratedin an ethanol series, embedded in Historesin (glycol methacrylate;Leica, Heidelberg, Germany), cut into 2-µm-thick sections,and stained with a solution of safranin, toluidine blue, andOrange G (Jernstedt et al., 1992). For scanning electron microscopy(SEM), the material was dehydrated in an ethanol series, critical-pointdried and coated with platinum–palladium. SEM observationswere made using a Hitachi S-800 microscope (10 kV).