Two new species of Diospyros (Ebenaceae) from New Guinea.

The genus Diospyros (Ebenaceae) is highly diverse throughout Malesia, and New Guinea is thought to host c.46 species. Here we present a taxonomic treatment of a group of vegetatively similar species from the region, characterised by the large, chartaceous leaves that develop a peculiarly dark colour when dried. As a result of examination of herbarium collections, we describe two species new to science, Diospyros multimaculata and D. tehno; we exclude the presence of D. rostrata from New Guinea; and we provide a key to these and the three other species with a similar habit, namely, D. janowskyi, D. fusicarpa and D. pulchra

The Pleuranthodium (Zingiberaceae) of Mount Wilhelm, Papua New Guinea

Three species of Pleuranthodium were encountered and collected during a survey of gingers at Mount Wilhelm, Chimbu Province, Papua New Guinea. Based on new material, the only previously known Pleuranthodium from this area, P. piundaundense , is described in more detail highlighting new diagnostic characters and its known distribution range is expanded based on identification of older specimens at Edinburgh from two other provinces. Two species so far only known from Mount Wilhelm could not be identified after studying all protologues, types and material from several herbaria. These are here described as new species, P. corniculatum and P. sagittatum . A key with both floral and vegetative characters is provided to all three species. Pleuranthodium corniculatum is distinct in having apical appendages on the calyx, and P. sagittatum has a wrinkled calyx. All species are described and illustrated, and conservation assessments are made

Beyond the Trees: A Comparison of Nonwoody Species, and Their Ecology, in Papua New Guinea Elevational Gradient Forest

This study appraises the richness of nonwoody species (ferns, herbs, lianas, palms, and shrubs) in 31 sites across undisturbed and disturbed forests in the lowland of Papua New Guinea (PNG) and at montane forest sites at 2,700 m a.s.l. The assessment was conducted following the PNG National Forest Inventory protocol. The results indicate that with 463 nonwoody species, the tropical forest of PNG has remarkable species richness. No significant difference was observed in richness among lowland, logged and pristine, and montane forests. The study shows that the richness of nonwoody species increases with elevation, but this trend is different when considering the taxonomic group separately. Palms and lianas decrease along the elevation, whereas ferns, herbs, and shrubs are positively correlated with elevation. The species composition between lowland forest and mountain sites is different, with a tree fern and an Araliaceae as an indicator of the mountain forest. The findings demonstrate a high taxonomic richness of nonwoody species in PNG, supporting previous research but highlighting the significant contribution of nonwoody species to the overall plant richness in a tropical habitat

New Guinea has the world’s richest island flora

New Guinea is the world’s largest tropical island and has fascinated naturalists for centuries1,2. Home to some of the best-preserved ecosystems on the planet3 and to intact ecological gradients—from mangroves to tropical alpine grasslands—that are unmatched in the Asia-Pacific region4,5, it is a globally recognized centre of biological and cultural diversity6,7. So far, however, there has been no attempt to critically catalogue the entire vascular plant diversity of New Guinea. Here we present the first, to our knowledge, expert-verified checklist of the vascular plants of mainland New Guinea and surrounding islands. Our publicly available checklist includes 13,634 species (68% endemic), 1,742 genera and 264 families—suggesting that New Guinea is the most floristically diverse island in the world. Expert knowledge is essential for building checklists in the digital era: reliance on online taxonomic resources alone would have inflated species counts by 22%. Species discovery shows no sign of levelling off, and we discuss steps to accelerate botanical research in the ‘Last Unknown’8