The holotype at B has been destroyed during WW II and no isotypes are known. C. De Candolle apparently has studied this specimen (see DC. Prod., 1869: 446). In his Revision of Philippine Piperaceae (1910: 408) he cites Merrill 4592, of which specimens are extant at G-DC, K, NY, US. That collection is considered as a candidate neotype [Mathieu, pers. comm., 2014]