Historical distribution of Sundaland's Dipterocarp rainforests at Quaternary glacial maxima.

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. We used species distribution models (SDMs) of 317 Dipterocarp species to estimate the geographic extent of appropriate climatic conditions for rainforest on Sundaland at the last glacial maximum (LGM). The SDMs suggest that the climate of central Sundaland at the LGM was suitable to sustain Dipterocarp rainforest, and that the presence of a previously suggested transequatorial savannah corridor at that time is unlikely. Our findings are supported by palynologic evidence, dynamic vegetation models, extant mammal and termite communities, vascular plant fatty acid stable isotopic compositions, and stable carbon isotopic compositions of cave guano profiles. Although Dipterocarp species richness was generally lower at the LGM, areas of high species richness were mostly found off the current islands and on the emergent Sunda Shelf, indicating substantial species migration and mixing during the transitions between the Quaternary glacial maxima and warm periods such as the present.

Parallel developments in floral adaptations to obligate moth pollination mutualism in tribe Phyllantheae (Phyllanthaceae).

Several groups within tribe Phyllantheae (Phyllanthaceae) formed, independently, an (obligate) pollination mutualism with Epicephala 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. Qualitative comparisons are made between non-moth-pollinated lineages, used as outgroups and various, independently moth-pollinated Phyllantheae clades, used as ingroups, thereby looking for parallel developments. The flowers of both sexes of various groups display similar, convergent morphological adaptations to the pollination system, likely to secure the obligate relationship and to improve efficiency. Sepals in both sexes, free or partly to highly connate, are commonly upright and form a narrow tube. The staminate flowers often have united, vertical stamens with the anthers along the androphore or on top of the androphore. Pistillate flowers generally reduce the stigmatic surface, either by making the stigmas shorter or by uniting them into a cone with a small opening at the top for pollen deposition. Less obvious is the reduction of the stigmatic papillae; these are often present in non-moth-pollinated taxa, but absent in the moth-pollinated species. The most diverging, parallel adaptations to moth pollination are currently found in the Palaeotropics, whereas in the Neotropics, some groups continue to also be pollinated by other insect groups and are morphologically less changed.

Phylogeny of palaeotropic Derris-like taxa (Fabaceae) based on chloroplast and nuclear DNA sequences shows reorganization of (infra)generic classifications is needed.

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. METHODS: Fifty species of palaeotropic Derris-like taxa were sampled, which is more than in former studies. Three chloroplast genes (trnK-matK, trnL-F IGS, and psbA-trnH IGS) and nuclear ribosomal ITS /5.8S were analyzed using parsimony and Bayesian methods. KEY RESULTS: Parsimony and Bayesian analyses of individual and combined markers show more or less similar tree topologies (only varying in terminal branches). The old-world monophyletic genera Aganope, Brachypterum, and Leptoderris are distinct from Derris s.s., and their generic status is here confirmed. Aganope may be classified into two or three subgeneric taxa. Paraderris has to be included in Derris s.s. to form a monophyletic group. The genera Philenoptera, Deguelia, and Lonchocarpus are monophyletic and distinct from each other and clearly separate from Derris s.s. Morphologically highly similar species of Derris s.s. are shown to be unrelated. Our study shows that previous infrageneric classifications of Derris are incorrect. Paraderris elliptica may contain several cryptic lineages that need further investigation. CONCLUSIONS: The concept of the genus Derris s.s. should be reorganized with a new generic circumscription by including Paraderris but excluding Brachypterum. Synapomorphic morphological features will be examined in future studies, and the status of the newly defined Derris and its closely related taxa will be formalized.

Delimitation of Sauropus (Phyllanthaceae) based on plastid matK and nuclear ribosomal ITS DNA Sequence data.

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. METHODS: Plastid matK and nuclear ribosomal ITS DNA sequence data for Sauropus and its allies were used to construct phylogenetic trees using maximum parsimony and Bayesian methods. KEY RESULTS: Within Phyllanthus, Sauropus can be split into the mainly south-east Asian Sauropus sensu stricto (s.s.) plus Breynia and the mainly Australian Sauropus (formerly Synostemon). Sauropus s.s. plus Breynia comprise two distinct clades; one is the combination of Sauropus sections Glochidioidei, Sauropus and Schizanthi and the other is the combination of Sauropus sections Cryptogynium and Hemisauropus and the monophyletic genus Breynia. CONCLUSIONS: Molecular data indicate that Synostemon should be reinstated at the same level as Sauropus s.s. and that Sauropus s.s. should be united with Breynia under the latter, older name. The molecular data corroborate only two of the five infrageneric groups of Sauropus recognized on the basis of morphological data.

A revision of Dissochaeta (Melastomataceae, Dissochaeteae).

Dissochaeta 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 Dalenia, Diplectria, Macrolenes and Omphalopus. Most of them are already regarded as synonyms of Dissochaeta except for Macrolenes which is considered a separate genus here as well. Dissochaeta is characterised by its scrambling habit, interpetiolar outgrowths, 4-merous flowers, dimorphic stamens and berry-like fruits. A taxonomic revision of Dissochaeta is presented, which includes references, a complete list of synonyms, detailed morphological descriptions of the species and an identification key, as well as information on the distribution, habitat and ecology, vernacular names, notes and lists of examined specimens. Fifty four species and two varieties of Dissochaeta are recognised. We designate several lectotypes, propose eleven new combinations and we describe one new species and one new variety.

Phyllanthus rufuschaneyi: a new nickel hyperaccumulator from Sabah (Borneo Island) with potential for tropical agromining.

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. RESULTS: One of the most promising species globally for agromining, is the here newly described species Phyllanthus rufuschaneyi. This species can be classified in subgenus Gomphidium on account of its staminate nectar disc and pistillate entire style and represents the most western species of this diverse group. The flower structure indicates that this species is probably pollinated by Epicephala moths. CONCLUSIONS: Phyllanthus rufuschaneyi is an extremely rare taxon in the wild, restricted to Lompoyou Hill near Kinabalu Park in Sabah, Malaysia. Its utilization in agromining will be a mechanism for conservation of the taxon, and highlights the importance of habitat and germplasm preservation if rare species are to be used in novel green technologies.

Actephila alanbakeri (Phyllanthaceae): a new nickel hyperaccumulating plant species from localised ultramafic outcrops in Sabah (Malaysia).

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. The most characteristic feature of Actephila alanbakeri are its knobbly fruits, but other diagnostic morphological characters are discussed and information about its ecology and rhizosphere and plant tissue chemistry is provided. This new species is one of the strongest known nickel hyperaccumulator plants in Southeast Asia with up to 14,700 µg g-1 (1.47 %) nickel in its leaves. The occurrences of Actephila alanbakeri on just two sites, both of which lie outside protected areas and are disturbed by recurring forest fires, combined with the small total numbers of individuals, render this species Endangered (EN) on the basis of IUCN Red List Criteria.

A New Classification of Ficus Subsection Urostigma (Moraceae) Based on Four Nuclear DNA Markers (ITS, ETS, G3pdh, and ncpGS), Morphology and Leaf Anatomy.

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.g., it is still unclear where to classify F. amplissima and F. rumphii. To clarify the circumscription of subsection Urostigma, a phylogenetic reconstruction based on four nuclear DNA markers (ITS, ETS, G3pdh, and ncpGS) combined with morphology and leaf anatomy is conducted. The phylogenetic tree based on the combined datasets shows that F. madagascariensis, a Madagascan species, is sister to the remainder of subsect. Urostigma. Ficus amplissima and F. rumphii, formerly constituting sect. Leucogyne, appear to be imbedded in subsect. Conosycea. The result of the phylogenetic analysis necessitates nomenclatural adjustments. A new classification of Ficus subsection Urostigma is presented along with the morphological and leaf anatomical apomorphies typical for the clades. Two new species are described ─ one in subsect. Urostigma, the other in Conosycea. One variety is raised to species level.

New Guinea: A Correlation between Accreting Areas and Dispersing Sapindaceae.

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.

Dated phylogenies of the sister genera Macaranga and Mallotus (Euphorbiaceae): congruence in historical biogeographic patterns?

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. The basal calibration point (crown node of all taxa used) was taken from literature and used for both taxa. The other three calibrations were based on fossils of which two were used per genus. We compared patterns of dispersal and diversification in Macaranga and Mallotus using ancestral area reconstruction in RASP (S-DIVA option) and contrasted our results with biogeographical and geological records to assess accuracy of inferred age estimates. A check of the fossil calibration point showed that the Japanese fossil, used for dating the divergence of Mallotus, probably had to be attached to a lower node, the stem node of all pioneer species, but even then the divergence time was still younger than the estimated age of the fossil. The African (only used in the Macaranga data set) and New Zealand fossils (used for both genera) seemed reliably placed. Our results are in line with existing geological data and the presence of stepping stones that provided dispersal pathways from Borneo to New Guinea-Australia, from Borneo to mainland Asia and additionally at least once to Africa and Madagascar via land and back to India via Indian Ocean island chains. The two genera show congruence in dispersal patterns, which corroborate divergence time estimates, although the overall mode and tempo of dispersal and diversification differ significantly as shown by distribution patterns of extant species.

A new species from Thailand and Burma, Dracaena kaweesakii Wilkin & Suksathan (Asparagaceae subfamily Nolinoideae).

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.