ABSTRACT
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.
Subject(s)
Biodiversity , Classification/methods , Islands , Plants/classification , Geographic Mapping , History, 18th Century , History, 19th Century , History, 20th Century , History, 21st Century , Internet , New Guinea , Species Specificity , Time FactorsABSTRACT
The angiosperm genus Logania R.Br. (Loganiaceae) is endemic to the mainland of Australia. A recent genetic study challenged the monophyly of Logania, suggesting that its two sections, Logania sect. Logania and Logania sect. Stomandra, do not group together. Additionally, the genus has a disjunct distribution, with a gap at the Nullarbor Plain in southern Australia. Therefore, Logania is a favourable candidate to gain insight into phylogenetic relationships and how these might intersect with Earth-history events. Our phylogenetic analyses of DNA sequences of two chloroplast markers (petD and rps16) showed that Logania sect. Logania and L. sect. Stomandra were each resolved as monophyletic, but the genus (as currently circumscribed) was not. Based on our Bayesian estimates of divergence times, the disjunct distributions within Logania sect. Stomandra could have been caused by flooding of the Eucla Basin. However, this biogeographical process cannot account for the distribution of Logania sect. Logania, with long-distance dispersal and establishment seeming more likely.