John Dransfield

Royal Botanic Gardens, Kew · Herbarium

Imbalance in species richness among related clades is a pervasive, yet incompletely understood feature of biodiversity. Comparison of species-poor and species-rich clades that have evolved within the same region can shed light on the mechanisms underlying this phenomenon. The long-isolated island of Madagascar is an ideal place for doing this. Mada...

A distinctive rattan from Borneo that can be distinguished from all other species of palm, even using its vegetative morphology alone, has remained undescribed for over 90 years due to the lack of reproductive material. We describe the species formally as new to science here.

New Guinea is the world’s largest tropical island and a globally significant biodiversity hotspot. Palms dominate the rainforests of New Guinea, from exquisite, forest floor palmlets to graceful canopy giants, and are vital for local people who depend on them for survival. Palms of New Guinea is the first comprehensive account of these immensely i...

The problem of polymorphism in the Calamus javensis complex has been examined by various techniques in several publications. A wide range of morphological variation was identified during these studies. Characters showing high variation were leaf sheath and ocrea morphology, number and arrangement of leaflets, length and arrangement of the rachillas...

With 178 species, palm subtribe Dypsidinae is one of the largest plant radiations on Madagascar. A well‐resolved species‐level phylogeny is required not only to unpick the drivers of this spectacular radiation, but also to define natural and useful generic limits in this taxonomically difficult group. The only recent taxonomic revision of Dypsidina...

Representatives of three genera of Livistoninae (Johannesteijsmannia, Licuala and Pholidocarpus) develop corky-warted fruits in contrast to fruit with smooth surfaces in most other representatives of the ‘apocarpous clade’ of Arecaceae subfamily Coryphoideae. The present developmental study is focused on revealing the anatomical peculiarities of th...

Well-supported phylogenies are a prerequisite for the study of the evolution and diversity of life on earth. The subfamily Calamoideae accounts for more than one fifth of the palm family (Arecaceae), occurs in tropical rainforests across the world, and supports a billion-dollar industry in rattan products. It contains ca. 550 species in 17 genera,...

Madagascar fait partie des territoires les plus importants dans le monde en termes de diversité spécifique pour les palmiers ou la famille des Arecaceae. Sur les quelques 2800 espèces reconnues dans le monde, l'ile possède à elle seule 208 espèces natives dont plus de 98% en sont endémiques. Certains taxons sont uniques du point de vue biologique c...

Madagascar is one of the most important areas in the world in terms of species diversity for palms, the family Arecaceae. Out of the approximately 2500 species recognized in the world, the island alone has 208 indigenous species, of which more than 98% are endemic, found naturally nowhere else. Some taxa are unique from a biological point of view b...

In this article we explain what DNA barcoding means and its utility for palm research and conservation.

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 diver...

Madagascar is one of our favorite places for palms; it has such an amazing diversity, plus getting to that diversity can be so exciting! The so-called Vondrozo forest is a prime example of both a thrilling journey and rich destination.

Madagascar is home to 208 indigenous palm species, almost all of them endemic and >80% of which are endangered. We undertook complete population census and sampling for genetic analysis of a relatively recently discovered giant fan palm, the Critically Endangered Tahina spectablis in 2008 and 2016. Our 2016 study included newly discovered populatio...

Plant traits are critical to plant form and function —including growth, survival and reproduction— and therefore shape fundamental aspects of population and ecosystem dynamics as well as ecosystem services. Here, we present a global species-level compilation of key functional traits for palms (Arecaceae), a plant family with keystone importance in...

Four new palm species are described in the genus Dypsis: three tree palms from the Masoala peninsula in north-eastern Madagascar (D. mijoroana sp. nov., D. ovojavavy sp. nov. and D. rabepierrei sp. nov.), and one understorey palm, D. aurantiaca sp. nov. from eastern-central Madagascar. Illustrations, a distribution map and conservation status are p...

Calamus javensis (Calamoideae) is a slender rattan common in tropical rainforests. The species is very polymorphic and forms a species complex together with some undetermined forms and the species C. acuminatus, C. amplijugus, C. congestiflorus, C. corrugatus, C. elopurensis, C. hypertrichosus, C. impar, and C. tenompokensis.Within the complex, the...

Each year we take a closer look at the status of plants in a particular region. This year we look at the current status of knowledge on plants in Madagascar.

As part of current research on the taxonomy of the palms (Arecaceae or Palmae) of New Guinea, ten new species of the rattan genus Calamus are described and illustrated here: Calamus baiyerensis, Calamus capillosus, Calamus erythrocarpus, Calamus heatubunii, Calamus jacobsii, Calamus katikii, Calamus kostermansii, Calamus papyraceus, Calamus pintaud...

Background: Understanding the patterns of biodiversity distribution and what influences them is a fundamental pre-requisite for effective conservation and sustainable utilisation of biodiversity. Such knowledge is increasingly urgent as biodiversity responds to the ongoing effects of global climate change. Nowhere is this more acute than in species...

Downloadable from http://resource.inbar.int/download/showdownload.php?lang=cn&id=167815

The tropical vegetation of Africa is characterized by high levels of species diversity but is undergoing important shifts in response to ongoing climate change and increasing anthropogenic pressures. Although our knowledge of plant species distribution patterns in the African tropics has been improving over the years, it remains limited. Here we pr...

The systematic biology of the palm family (Arecaceae) is probably better known than that of any other tropical plant family of comparable size. As a result, the palms are now regarded as a model group for tropical rain forest research. Ten years ago, the first phylogenetic classification of palms was established as a foundation for the second editi...

Four species are recognized in the understorey palm genus Johannesteijsmannia (Arecaceae), all of which occur in close geographical proximity in the Malay Peninsula. We hypothesize that overlapping distributions are maintained by a lack of gene flow among species and that segregation along morphological trait or environmental axes confers ecologica...

Palms (Arecaceae) are conspicuous in traditional medicine in Africa, contributing to health care of rural and urban dwellers. Palm species richness in Africa is much lower than in either tropical America or tropical Asia, whereas palm species richness in Madagascar is among the highest in the world when its area is taken into consideration. The Afr...

The tropical vegetation of Africa is characterized by high levels of species diversity but is undergoing important shifts in response to ongoing climate change and increasing anthropogenic pressures. Although our knowledge of plant species distribution patterns in the African tropics has been improving over the years, it remains limited. Here we pr...

Throughout SE Asia, palms are important in agroforestry systems and homegardens. Most species are used for multiple purposes based on both physical and nutritional properties of the palms. Except for a few commodities of worldwide importance such as palm oil and coconut, many palm products either do not figure in trade statistics, or they are merge...

Palms are keystone species in tropical ecosystems and provide essential ecosystem services to rural people worldwide. However, many palm species are threatened by habitat loss and over-exploitation. Furthermore, palms are sensitive to climate and thus vulnerable to future climate changes. Here, we provide a first quantitative assessment of the futu...

Daemonorops komsaryi (Arecaceae), a new species of rattan from the Bird’s Head Peninsula in West Papua, Indonesia, is described and illustrated. This species closely resembles D. calapparia, but is distinguished by having more than 60 leaflets on each side of the leaf rachis, and in having slender, rigid, long blackish-brown spines and long petiole...

A new species of the rattan genus Daemonorops is recorded for Java, Daemonorops sedisspirituum. D. sedisspirituum is closely allied to D. hirsuta and D. oblonga but differs in stem size, sheath armature, and seed surface. Key Words. Indonesia, Malesia, rattan.

The establishment of baseline IUCN Red List assessments for plants is a crucial step in conservation planning. Nowhere is this more important than in biodiversity hotspots that are subject to significant anthropogenic pressures, such as Madagascar. Here, all Madagascar palm species are assessed using the IUCN Red List categories and criteria, versi...

Zipp. ex Blume (Rumphia 2: 75. 1839), develop from inflorescences with numerous slender rachillae. At the very base of each rachilla there are one to five pistillate flowers, the rest of the rachillae being slender and purely staminate. This staminate portion dries and falls after anthesis, resulting in an infructescence of spicate appearance that...

The rattan genus Calamus, the largest genus of palms (Arecaceae or Palmae), is poorly known in New Guinea. In preparation for a monograph of Calamus in New Guinea, we describe and illustrate fourteen new species here: Calamus badius, C. barfodii, C. bulubabi, C. cheirophyllus, C. croftii, C. johnsii, C. lucysmithiae, C. nanduensis, C. oresbius, C....

Calamus kebariensis (Arecaceae or Palmae), a new species of rattan from the Bird’s Head Peninsula in West Papua, Indonesia, is described and illustrated. This species, which, among the New Guinea Calamus species, most closely resembles C. cuthbertsonii and C. spanostachys, is distinguished by its short and extremely slender stems, finely pinnate le...

Tuberous, water-storing roots in Ravenea xerophila are described and illustrated. They are the first such roots ever recorded for a palm. Tuberous roots are probably an adaptation to the xeric habitat in which this palm grows in southern Madagascar.

Past climatic changes have caused extinction, speciation, and range dynamics, but assessing the influence of past multimillion-year climatic imprints on present-day biodiversity patterns remains challenging. We analyzed a new continental-scale data set to examine the importance of paleoclimatic effects on current gradients in African palm richness...

The distribution of rainforest in many regions across the Earth was strongly affected by Pleistocene ice ages. However, the extent to which these dynamics are still important for modern-day biodiversity patterns within tropical biodiversity hotspots has not been assessed. We employ a comprehensive dataset of Madagascan palms (Arecaceae) and climate...

Tsitongambarika is a forested area in the extreme southeast of Madagascar, lying just to the north of Taolagnaro (Fort Dauphin). Although it harbors substantial areas of good forest cover and is moderately easy to access, botanical exploration of the area has only recently begun.

Madagascar has a high diversity of endemic palm species and the Masoala Peninsula is a hotspot for their diversity. Several species are critically endangered and their populations known to be in decline due to a combination of land clearance, destructive harvesting for heart of palm and potentially unsustainable commercial seed collection. The crit...

Orania Zipp. (Oranieae: Arecoideae: Arecaceae) is a genus of solitary, single stemmed tree palms consisting of 28 species, of which 11 species are new and described for the first time in this paper. The genus has an interesting disjunct distribution, with 25 species found in Malesia and three species confined to Madagascar. The 11 new species, O. b...

The Malesian genus Eugeissona, with six species, is sister to all other Calamoideae, which are in turn sister to all other Arecaceae. The structure of its gynoecium and fruit is thus potentially of great interest in understanding gynoecium evolution in calamoid palms and in Arecaceae as a whole. The wall of the incompletely trilocular gynoecium of...

The palm genus Areca is widespread in tropical Asia and includes the economically important betel nut palm, A. catechu. The genus has three centres of high species diversity: the Sunda Region, the Philippines and East Malesia (to the east of Wallace's line). The taxonomy of the genus in East Malesia has been neglected. Prior to this study, 19 speci...

Aim The relative importance of current climate and past historical legacies is hotly debated. Here, we assess their role in determining the global distribution and diversity patterns of palms (Arecaceae), a widespread, species-rich group of keystone ecological importance in tropical ecosystems. Location Global. Methods We assembled country-level sp...

Madagascar has an extraordinary palm fl ora, diverse in species and evolution-ary lines, a diversity that poses interesting evolutionary questions. The palms in Madagascar are in stark contrast to two other families of largely tropical mono-cotyledons, Zingiberaceae and Araceae , where the Madagascar representation is low in diversity despite being...

Fourteen new species of palms (Arecaceae) from Madagascar are described and named, based on material collected over the last 15 years. Twelve species belong to the genus Dypsis, namely D. andilamenensis Rakotoarin. & J. Dransf., D. anjae Rakotoarin. & J. Dransf., D. betsimisarakae Rakotoarin. & J. Dransf., D. culminis Rakotoarin. & J. Dransf., D. d...

Most of the Earth's biodiversity resides in the tropics. However, a comprehensive understanding of which factors control range limits of tropical species is still lacking. Climate is often thought to be the predominant range-determining mechanism at large spatial scales. Alternatively, species’ ranges may be controlled by soil or other environmenta...

Fourteen new species of palms (Arecaceae) from Madagascar are described and named, based on material collected over the last 15 years. Twelve species belong to the genus Dypsis, namely D. andilamenensis Rakotoarin. & J. Dransf., D. anjae Rakotoarin. & J. Dransf., D. betsimisarakae Rakotoarin. & J. Dransf., D. culminis Rakotoarin. & J. Dransf., D. d...

Context – Palms are among the most diverse families of plants in Madagascar but knowledge of the family remains incomplete. Compared with other plants, only few botanists have actively worked on the family. Aim – This paper aims to relate palm research in Madagascar chronologically since the 18th century by highlighting the evolution of knowledge o...

Within the palm family, molecular analyses have resulted in a need to re-evaluate characters previously considered useful to establish hypotheses of relationships among groups. Recent phylogenetic analyses of tribe Chamaedoreeae have shown that characters traditionally used as strong indicators of relationship, such as presence of solitary flowers...

Within the palm family, molecular analyses have resulted in a need to re­evaluate characters previously considered useful to establish hypotheses of relationships among groups. Recent phylogenetic analyses of tribe Chamaedoreeae have shown that characters traditionally used as strong indicators of relationship, such as presence of solitary flowers...

Supertree and supermatrix methods have great potential in the quest to build the tree of life and yet they remain controversial, with most workers opting for one approach or the other, but rarely both. Here, we employed both methods to construct phylogenetic trees of all genera of palms (Arecaceae/Palmae), an iconic angiosperm family of great econo...

Cyrtostachys Blume (Areceae: Arecaceae) is treated in this study as a genus of tree palms with a disjunct distribution pattern across Malesia and consisting of seven species. Three species are newly recognised (C. bakeri Heatubun, C. barbata Heatubun and C. excelsa Heatubun). Five previously accepted species (C. brassii Burret, C. kisu Becc., C. mi...

C. Kremen et al. (“Aligning conservation priorities across taxa in Madagascar with high-resolution planning tools,” Reports, 11 April, p. 222) identified the optimal sites for expansion of Madagascar's land area under protection, using advanced conservation planning techniques at an

The morphology and development of inflorescences in 14 genera and 52 species of rattans and related genera of Lepidocaryoid palms were examined. Inflorescences are free (not adnate) in Ancistrophyllum, Eremospatha and Oncocalamus. Adnation between the inflorescence and internode above occurs in Korthalsia, Myrialepis, Plectocomia and Plectocomiopsi...

DRANSFIELD, J. & MOGEA, J. P., 1984. The flowering behaviour of Arenga (Palmae: Caryotoideae). The palm genus Armga, with 21 species, displays remarkable variation in flowering behaviour, involving both pleonanthy and hapaxanthy with basipetal production of inflorescences; inflorescences may be bisexual or unisexual, solitary or multiple. The ecolo...

Globally, priority areas for biodiversity are relatively well known, yet few detailed plans exist to direct conservation action within them, despite urgent need. Madagascar, like other globally recognized biodiversity hot spots, has complex spatial patterns of endemism that differ among taxonomic groups, creating challenges for the selection of wit...

Based on previously published phylogenetic research, the genus Calospatha Becc. (Calamoideae) is placed in synonymy within Calamus L. The new combination, Calamus calospathus (Ridl.) W. J. Baker & J. Dransf. is made.

Tahina J.Dransf. & Rakotoarinivo, gen. nov. (Arecaceae) is described as a new genus from north-western Madagascar, with a single species T. spectabilis J.Dransf. & Rakotoarinivo, sp. nov.Tahina is included within tribe Chuniophoeniceae of subfamily Coryphoideae, based on the strictly tubular imbricate rachilla bracts, the flowers grouped in cincinn...

This book can be freely downloaded at https://doi.org/10.34885/92

The Ceroxyloideae is a small but heterogeneous subfamily of palms (Arecaceae, Palmae). It includes a Caribbean lineage (tribe Cyclospathae), a southern hemisphere disjunction (tribe Ceroxyleae), and an amphi-Andean element (tribe Phytelepheae), until recently considered a distinct subfamily (Phytelephantoideae) due to its highly derived morphology....

Madagascar has a highly distinctive flora and is one of the world biodiversity hot spots. There are more than 170 species of palms, the majority of which are vulnerable, endangered or critically endangered endemics. Palms are utilized for many human uses, many of which lead to plant death or seed harvesting. Combined with reduced populations result...