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| Registros recuperados: 60 | |
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| Bouman, R.W.; Keβler, P.J.A.; Telford, I.R.H.; Bruhl, J.J.; Welzen, P.C. van. |
| Over two centuries of taxonomic studies on the species rich genus Phyllanthus have culminated in a broad and complicated classification with many subgenera and (sub)sections. Past taxonomic work has only focused on local revisions, mostly because of the size of the genus. In this study we aim to summarize most of the taxonomic work in a list containing the infrageneric delimitations of Phyllanthus. This work will serve as a reference, placing most currently recognized species in subgenera and if possible, in sections for further study. Here we recognize 880 species of Phyllanthus, classified in 18 subgenera, 70 sections and 14 subsections. A few taxonomic changes are necessary to reconcile published phylogenetic data with the current classification.... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Infrageneric taxonomy; Pantropical; Paraphyletic; Phyllanthaceae; Phyllanthus. |
| Ano: 2018 |
URL: http://www.repository.naturalis.nl/record/670219 |
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| Welzen, P.C. van. |
| Fourteen species of Sauropus are recognised for Malesia, 21 for Thailand. Two species are described as new, S. asymmetricus of Sumatra and S. shawii of Borneo. Many new synonyms, especially for S. androgynus and S. rhamnoides, are provided. The latter two species have a much wider distribution than described before and both are difficult to separate from each other. A phylogeny based on morphological and palynological data proved futile, but showed that Sauropus together with Breynia and Glochidion are embedded in the paraphyletic Phyllanthus. Most species which formerly belonged to Synostemon and are now included in Sauropus are probably, with the exception of S. bacciformis, related to Breynia and Glochidion. Because of the poor phylogenetic results the... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Euphorbiaceae; Sauropus; Synostemon; Malesia; Thailand. |
| Ano: 2003 |
URL: http://www.repository.naturalis.nl/record/525088 |
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| Ottens-Treurniet, M.A.D.; Welzen, P.C. van. |
| The genus Blumeodendron (Euphorbiaceae) comprises nine species and is distributed from the Andaman Islands and Myanmar in the west through Malesia to the Bismarck Archipelago in the east. Two species are newly described, B. gesinus, with ridged fruits, and B. endocarpum, with a thickened endocarp around each seed. Three former synonyms, B. novoguineense (new name for Bennettia papuanum), B. philippinense and B. subrotundifolium, are reinstated as species. Two important characters were newly discovered, the presence of small lepidote hairs in all species and the indehiscent fruit of B. endocarpum |
| Tipo: Article / Letter to the editor |
Palavras-chave: Blumeodendron; Euphorbiaceae; Malesia; Revision; Taxonomy. |
| Ano: 2016 |
URL: http://www.repository.naturalis.nl/record/607279 |
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| Welzen, P.C. van. |
| Dicoelia was always considered to be a monotypic genus. Typical are the hooded (cucullate) petals that form cavities in which juvenile thecae of adjacent stamens are protected. Specimens of Sumatra appear to represent a new species. The Sumatran specimens have stipules that fall slightly later and they show morphological differences in the pistillate petals, pistillode, columella and hilum. Newly described structures are disc glands (thought to be absent), probably not functional, but present in the flowers of both sexes and a gynophore in the pistillate flowers. Dicoelia is considered as a member of the Phyllanthaceae conforming with the latest molecular phylogenetic results; a classification that agrees with the presence of two ovules per locule. |
| Tipo: Article / Letter to the editor |
Palavras-chave: Dicoelia; Disc glands; Euphorbiaceae; Gynophore; Malesia; Phyllanthaceae. |
| Ano: 2011 |
URL: http://www.repository.naturalis.nl/record/524830 |
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| Welzen, P.C. van; Ham, R.W.J.M. van der; Heel, W.A. van; Uffelen, G.A. van; Wilde, W.J.J.O. de; Kalkman, C.; Valkenburg, Johan L.C.H. van. |
| This project of the Royal Botanic Garden Edinburgh aims to provide regional manuals and on-line identification computer programs to the timber species of Dipterocarpaceae. The Singapore manual is a first trial, later editions should include other islands in the Malay Archipelago. The possibility is also offered to have tailor-made manuals for specific regions against cost price. Many data have been gathered, especially vegetative characters one can readily observe while standing underneath these enormous trees. In this respect the database will be very useful, because due to the very irregular flowering of the Dipterocarpaceae, flowers and fruits are usually unavailable, and even if they are present, they are found high in the tree. |
| Tipo: Article / Letter to the editor |
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| Ano: 1996 |
URL: http://www.repository.naturalis.nl/record/525707 |
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| Welzen, P.C. van; Hengst, S. den. |
| Characteristic for the genus Mastersia are the indehiscent pods with seeds with elongated funicles. Within this genus only two species are recognized: M. assamica Benth. from Assam and M. bakeri (Koord.) Backer from Borneo, Celebes and the Moluccas. Both species are considered closely related; distinctive characters are found in the bracteoles, wing petals, keel petal and pod. Mastersia is placed within the Phaseoleae in the subtribe Glycininae-Glycinastrae. The distribution pattern of both species is discussed. |
| Tipo: Article / Letter to the editor |
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| Ano: 1984 |
URL: http://www.repository.naturalis.nl/record/525542 |
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| Kulju, K.K.M.; Sierra, S.E.C.; Welzen, P.C. van. |
| A recent molecular phylogenetic study of Mallotus and related genera showed that three small Asiatic genera are clearly part of a strongly supported main Mallotus clade (Mallotus s.s. clade), rendering the genus paraphyletic. In this paper these genera, Neotrewia, Octospermum and Trewia, are merged with Mallotus. The monotypic Neotrewia and Octospermum were originally described within Mallotus and are now transferred back to it. Trewia was never included in Mallotus; it has two distinct species, for which new combinations within Mallotus are made. A full taxonomic treatment with descriptions, distribution maps and drawings is given for the species transferred, and a new generic description for Mallotus is provided. The morphology of the newly transferred... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Rottlerinae; Mallotus; Neotrewia; Octospermum; Trewia; Malesia; Taxonomy. |
| Ano: 2007 |
URL: http://www.repository.naturalis.nl/record/524934 |
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| Sirichamorn, Y.; Adema, F.A.C.B.; Welzen, P.C. van. |
| Derris solorioides is described as a new species and illustrated. This species is only the second calciphilous and true-paniculate species of Derris ever recorded. The species was found in isolated and protected limestone areas surrounded by agricultural areas in Nakhon Sawan province, North-Central Thailand. It is characterized by its rather smaller flowers but with more ovules than other species of Derris, and 1-winged pods showing a dark-coloured pericarp around the seeds without thickening of the pericarp. The characters of the pods are similar to those found in Solori, a genus once synonymized with Derris and, therefore, the epithet ‘solorioides’ was assigned. This species appeared to be a distinct taxon in the molecular phylogeny, separate from its... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Derris; Limestone; Solori; Thailand; True panicle. |
| Ano: 2014 |
URL: http://www.repository.naturalis.nl/record/525723 |
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| Sagun, V.G.; Levin, G.A.; Welzen, P.C. van. |
| Twenty-eight species of Acalypha are recognized in Malesia. Acalypha paniculata is the sole member of subgenus Linostachys in Malesia and the rest of the species belong to subgenus Acalypha. Four previously synonymized species are resurrected as distinct species, namely A. angatensis, A. cardiophylla var. cardiophylla, A. grandis, and A. wilkesiana. Four species names are newly reduced to synonymy. The molecular phylogenetic analyses indicate that Acalypha is monophyletic, as is the subgenus Acalypha. The early-diverging lineages in the genus, and its closest outgroup, consist of African species. The Malesian species do not form a monophyletic group although the molecular data strongly support two small clades within the region that are morphologically... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Acalypha; Euphorbiaceae; Malesia; Phylogeny. |
| Ano: 2010 |
URL: http://www.repository.naturalis.nl/record/526264 |
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| Welzen, P.C. van; Valen, R.P. van; Valkenburg, J.A.. |
| The database system which is presently implemented in the Rijksherbarium/Hortus Botanicus, called LBASE, will also serve as the future databank for the Flora Malesiana project. The system will contain information about specimens, persons, literature, taxa, and nomenclature. LBASE can serve many functions such as generating literature/nomenclature headings above descriptions, identification lists, listings of vernacular names, distribution maps, etc; but also administrative functions for library and collection maintenance. Data capture will be from existing databases, current revisions, and new/loan material. Data from earlier revisions will only be added if additional funding becomes available. In the future LBASE may grow into some kind of expert system... |
| Tipo: Article / Letter to the editor |
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| Ano: 1992 |
URL: http://www.repository.naturalis.nl/record/533261 |
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| Adema, F.; Leenhouts, P.W.; Welzen, P.C. van. |
| Trees, shrubs or lianas, rarely herbaceous climbers; monoecious, rarely dioecious or polygamous. Indumentum usually of solitary, simple hairs, sometimes also of two-branched hairs, stellate bundles of hairs, or scale hairs (then young parts, buds, and inflorescences viscid). Leaves spirally arranged, rarely opposite or whorled, simple, biternate, digitate or (bi)pinnate; true stipules usually absent, pseudo-stipules sometimes present. Leaflets alternate to opposite, symmetric to distinctly asymmetric, entire or dentate to serrate or crenate. Inflorescences axillary, often together pseudoterminal, terminal or ramiflorous, thyrsoid, with or without branches; bracts and bracteoles present. Flowers usually unisexual, rarely bisexual, actinomorphic or... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Sapindaceae. |
| Ano: 1994 |
URL: http://www.repository.naturalis.nl/record/532629 |
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| Prud’homme van Reine, W.F.; Welzen, P.C. van; Stroo, Arjan; Heel, Willem A. van; Grayer-Barkmeijer, Renée. |
| This important book, written in somewhat baroque and not always clear English, provides a wealth of information for all those studying or working with Cyanoprokaryotes. That are the organisms usually known as Cyanobacteria or still just bluegreen algae. A modern book on identification, but only on the unicellular or colonial members, not on the important filamentous groups. Two parts will follow later. Although in the ‘Anschrift der Authoren’ it is indicated that Professor Anagnostidis has died, no further information is given about that sad event. The introduction is very important for users and reviewers. The editors printed in bold “Please, read this chapter” and they are right. Without reading this no-one would know that the book contains “a review of... |
| Tipo: Article / Letter to the editor |
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| Ano: 1999 |
URL: http://www.repository.naturalis.nl/record/525694 |
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| Welzen, P.C. van. |
| A monograph of the genus Guioa Cav. (Sapindaceae) is presented. 64 species are recognized; one species, Guioa subfalcata, is regarded as a dubious species. A general key and several regional keys provide access to the species. One species, Guioa glauca, is subdivided into two varieties. The infrageneric classification contains three levels: subgenera, sections, and subsections. The classification is based on a phylogenetic analysis of the genus. The leaf anatomy was studied besides the macromorphology. This resulted in 67 characters for a cladistic analysis. The outcome of the initial analysis was rejected for several reasons (chapter 11.6). An alteration of the method resulted in an acceptable cladogram: the genus was subdivided, based on several... |
| Tipo: Article / Letter to the editor |
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| Ano: 1989 |
URL: http://www.repository.naturalis.nl/record/508231 |
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| Heijkoop, M.; Welzen, P.C. van. |
| The genus Actephila (Phyllanthaceae) is distributed from India in the north-west to Thailand and via Malesia to the Melanesian Islands and Australia in the south-east. Eleven species are recognized of which three are newly described, A. discoidea with long leaf apices and a fleshy nectar discs, A. emarginata with an emarginate leaf base, and A. stipularis with large stipules. Further, A. javanica is synonymized with A. excelsa; and a former synonym or separate variety, A. excelsa var. acuminata, is recognized as distinct species, but had to be synonymized under A. subsessilis. Actephila puberula, not present in Malesia, but often synonymized with A. excelsa, is kept separate because of the hairy ovary and different base of the leaf blades. |
| Tipo: Article / Letter to the editor |
Palavras-chave: Actephila; Asia; Malesia; Phyllanthaceae; Revision; Taxonomy. |
| Ano: 2017 |
URL: http://www.repository.naturalis.nl/record/623378 |
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| Registros recuperados: 60 | |
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