Publications by authors named "Peter van Welzen"

Several groups within tribe Phyllantheae (Phyllanthaceae) formed, independently, an (obligate) pollination mutualism with moths, which originally had been parasitic. In this pollination system, female moths actively collect pollen from staminate flowers and deposit it on the stigma of pistillate flowers, after which they place at least one egg in or against the ovary. The high pollination rate makes the system beneficial for the plants, whereas the larvae are provided with food (part of the developing seeds) and some protection against predation.

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New Guinea is the world's largest tropical island and has fascinated naturalists for centuries. Home to some of the best-preserved ecosystems on the planet and to intact ecological gradients-from mangroves to tropical alpine grasslands-that are unmatched in the Asia-Pacific region, it is a globally recognized centre of biological and cultural diversity. So far, however, there has been no attempt to critically catalogue the entire vascular plant diversity of New Guinea.

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is a plant genus of woody climbers, classified in the tribe Dissochaeteae (Melastomataceae). The taxonomic history of the genus is complicated and includes some allied genera like , , and . Most of them are already regarded as synonyms of except for which is considered a separate genus here as well.

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Background: Nickel hyperaccumulator plants are of much interest for their evolution and unique ecophysiology, and also for potential applications in agromining-a novel technology that uses plants to extract valuable metals from soil. The majority of nickel hyperaccumulators are known from ultramafic soils in tropical regions (Cuba, New Caledonia and Southeast Asia), and one genus, Phyllanthus (Phyllanthaceae), is globally the most represented taxonomic entity. A number of tropical Phyllanthus-species have the potential to be used as 'metal crops' in agromining operations mainly because of their ease in cultivation and their ability to attain high nickel concentrations and biomass yields.

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The Malaysian state of Sabah on the Island of Borneo is emerging as a hotspot for nickel hyperaccumulator species with at least 25 such species discovered to date. New discoveries of the hyperaccumulation trait in described taxa, as well as taxonomical novelties that are nickel hyperaccumulators, continue to be made. Here we describe a new nickel hyperaccumulating species of Actephila (Phyllanthaceae) originating from two known populations on ultramafic soils in Sabah.

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Ficus subsection Urostigma as currently circumscribed contains 27 species, distributed in Africa, Asia, Australia and the Pacific, and is of key importance to understand the origin and evolution of Ficus and the fig-wasp mutualism. The species of subsection Urostigma are very variable in morphological characters and exhibit a wide range of often partly overlapping distributions, which makes identification often difficult. The systematic classification within and between this subsection and others is problematic, e.

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The extent of Dipterocarp rainforests on the emergent Sundaland landmass in Southeast Asia during Quaternary glaciations remains a key question. A better understanding of the biogeographic history of Sundaland could help explain current patterns of biodiversity and support the development of effective forest conservation strategies. Dipterocarpaceae trees dominate the rainforests of Sundaland, and their distributions serve as a proxy for rainforest extent.

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Molecular phylogenies and estimates of divergence times within the sister genera Macaranga and Mallotus were estimated using Bayesian relaxed clock analyses of two generic data sets, one per genus. Both data sets were based on different molecular markers and largely different samples. Per genus three calibration points were utilised.

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A morphologically distinct element of the group of Dracaena species from Thailand and Burma with undifferentiated leaf sheaths, no leaf blade central costa, free tepals and free thickened filaments known as Chan nuu or Chan pha krai in Thai is shown to be a distinct species, Dracaena kaweesakii Wilkin & Suksathan based on habit, leaf base and margin, inflorescence axis indumentum and floral characters. It is described and illustrated. Ecological and conservation status assessment information are provided.

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Premise Of The Study: Palaeotropic Derris-like taxa (family Fabaceae, tribe Millettieae) comprise 6-9 genera. They are well known as important sources of rotenone toxin, which are used as organic insecticide and fish poison. However, their phylogenetic relationships and classification are still problematic due to insufficient sampling and high morphological variability.

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Background And Aims: A recent molecular phylogenetic study showed that Sauropus is deeply embedded within Phyllanthus together with its allies, Breynia and Glochidion. As relationships within Sauropus are still problematic and the relationship with Breynia has long been doubted, more molecular data are needed to test/corroborate such a broad definition of Phyllanthus. This study aims to clarify the status and delimitation of Sauropus and establish its position within Phyllanthaceae.

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A correlation between accreting (hybridizing) areas and dispersing taxa (several genera of Southeast Asian/Australian Sapindaceae) is theoretically impossible in cladistic biogeography. However, in particular circumstances (primitive absence followed by colonization and speciation) cladistic methods can reconstruct (part of) the historical sequence of accretion. In this example, the phases in the accretion history of more than 30 terranes of the northern half of New Guinea correspond reasonably well with the generalized area cladogram of the Sapindaceae.

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