The Podocarpus species of Ambon (Podocarpaceae)

One of the first descriptions of a plant recognizably of the important genus Podocarpus was the Lignum emanum of Rumphius in 1743. Included was a sketch of the leaf and the mention of provenance, namely: Amboina in high rocky mountains, Ema and Hitu regions. When D. Don described Podocarpus neriifolius in 1824 he gave Lignum emanum as a synonym, crediting Wallich with this determination. Indeed, Podocarpus neriifolius has been collected on Ambon and was the first post-Linnean species of Podocarpus to be described for the Malesian region, even though the type specimens came from Nepal. In 1847 Endlicher transferred the synonymy of Lignum emanum to Podocarpus bracteatus Blume, the second and only other species of the genus pertaining to Malesia described up to that time. Podocarpus bracteatus was described from Java and extends into New Guinea although it has not in fact been identified from Ambon. In this same year Blume described a group of new species, one of which he specifically related to Lignum emanum with the name Podocarpus rumphii and by synonymy. His type material derived from New Guinea, even though P. rumphii certainly is known from Ambon. Numerous subsequent authors have accepted the synonymy of Lignum emanum with Podocarpus rumphii. A new approach in identifying the species of Rumphius was taken in 1913 by C. B. Robinson who attempted to duplicate the collections by visiting the actual locations given by Rumphius. He identified his collection number 309 as representing Lignum emanum. This specimen, however, is not Podocarpus rumphii. In writing on Rumphius’s Herbarium in 1917, Merrill suggested as much and called for a critical comparison. Two studies covering Malesian Podocarpus have since appeared. The first, by Wasscher in 1941, makes no distinction between the type represented by Robinson 309 and Podocarpus rumphii. A substantial portion of the specimens cited by Wasscher under P. rumphii belong in P. neriifolius. The second study by Gray in 1958 is much the same in that a similar mixture of material is cited. Incredibly, the only specimen common among the considerable lists of both Wasscher and Gray is Robinson 309 which Merrill had already questioned as belonging to P. rumphii. Gray had not seen the type material of this latter species and was really not at all clear concerning its true character. Some of the specimens belonging to the taxon represented by Robinson 309 were included by Gray under the new species Podocarpus ridleyi of Malaya because of the extra resin canals and the continuous upper hypoderm and in spite of a distinct difference in leaf shape and ecological habitat.