Nepenthes rhombicaulis Sumatra, near Prapat, G. Pangulubao, 1700-1900 m, ., 29 March 1972, Kurata 4300 Sumatra, near Prapat, G. Pangulubao, 1700-1900 m, ., 29 March 1972, Kurata 4300 (SING)