Sandakania (No.12 Dec 1998)

A new species, Parartocarpus spinulosus, is described from Sabah, so far known only from sites with ultramafic geology. Parartocarpus was revised by Jarrett (1960). In my revision of the genus Parartocarpus for the Tree Flora of Sabah and Sarawak, two collections from the Telupid district in Sabah representing a peculiar taxon were noted. Jarrett annotated a Kew duplicate of the earlier (1976) collection Leopold SAN 43885 as P. venenosus ssp. borneensis (Zoll. & Mor.) Jarrett. Apparently, the usually strongly emarginate apex, the strongly recurved margin and the spinulose, sandpaper-like surface of the leaf in this specimen were overlooked. Parartocarp venenosus ssp. borneensis (Zoll. & Mor.) Jarrett sometimes has leaves with a rounded to emarginate apex, but not the sandpaper-like surface or the conspicuously recurved margin. The second collection, Soepadmo et al. FRI 41312, made in 1994, also has the same characters. The distinction between these two taxa is well shown by studies of leaf surface by electron microscopy which reveals differing hair types and stomata. A study of the Malesian material revealed that the unusual taxon noted here is unnamed. Moreover, there are also distinctive characters in the flowering and fruiting heads that clearly distinguish this taxon from others.