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| Registros recuperados: 60 | |
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| Slik, J.W.F.; Welzen, P.C. van. |
| Mallotus sections Hancea and Stylanthus from Malesia are revised. Descriptions, distribution ranges, habit drawings and keys to all the species in these two sections are provided. The diagnostic characters for the sections are discussed briefly in the section headings. Mallotus section Hancea is defined more precisely than before, resulting in the exclusion of 4 species from this section (M. brachythyrsus, M. havilandii, M. insularum (new rank) and M. miquelianus). Mallotus beccarii is synonymised with M. brachythyrsus, and M. tenuipes with M. penangensis. This section contains 12 species. In Mallotus section Stylanthus, M. oblongifolius is synonymised with M. peltatus. This section contains 6 species. |
| Tipo: Article / Letter to the editor |
Palavras-chave: Mallotus; Section Hancea; Section Stylanthus; Malesia; Taxonomy. |
| Ano: 2001 |
URL: http://www.repository.naturalis.nl/record/525368 |
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| Balgooy, M.M.J. van; Lowry II, P.P.; Philipson, W.R.; Coode, M.J.E.; Nielsen, I.; Dransfield, J.; Meijden, R. van der; Schrader, T.; Adema, F.; Welzen, P.C. van. |
| Name: Alseuosmiaceae Airy Shaw, Kew Bull. 18 (1965) 249. Family: Alseuosmiaceae. |
| Tipo: Article / Letter to the editor |
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| Ano: 1993 |
URL: http://www.repository.naturalis.nl/record/509475 |
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| Sierra, S.E.C.; Aparicio, M.; Gebraad, M.J.H.; Kulju, K.K.M.; Welzen, P.C. van. |
| The range of diagnostic morphological features in the whole genus Mallotus is reviewed as background to the taxonomic treatment of section Rottleropsis s.l. Special emphasis is given to the indumentum, habit, stipules, leaves, extrafloral nectaries, domatia, inflorescences, flowers, pollen and fruits. Notes on the geographical distribution, ecology, pollinators, fruit and seed dispersal, and uses of the genus are also presented. The section Axenfeldia is reduced to sect. Rottleropsis on account of the absence of suitable morphological characters to distinguish them. A taxonomic revision of 38 species of sect. Rottleropsis s.l. from Malesia, Thailand and Africa is presented, together with regional and synoptical identification keys, distribution maps and... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Euphorbiaceae; Axenfeldia; Mallotus; Rottleropsis; Malesia; Thailand; Africa. |
| Ano: 2007 |
URL: http://www.repository.naturalis.nl/record/524640 |
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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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| Welzen, P.C. van; Slik, J.W.F.. |
| Distribution patterns or the recognition of phytogeographical areas is usually based on the presence and absence of species. The taxa on which the analyses are based remain virtually anonymous. Here we want to determine which Malesian plant families (within the sample) are responsible for species richness and composition patterns. The other aim is to determine whether the different islands groups in Southeast Asia can be grouped into separate phytogeographical areas. A Principal Coordinates Analysis (PCO) showed the presence of three phytogeographical areas within Malesia: The Sunda Shelf (Malay Peninsula, Sumatra, Borneo) in the west, the Sahul Shelf (New Guinea) in the east, and all remaining central areas forming Wallacea. The latter can be divided into... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Floristic patterns; Malay Archipelago; Malesia; PCO; Plant families; Species richness. |
| Ano: 2009 |
URL: http://www.repository.naturalis.nl/record/525639 |
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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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| Welzen, P.C. van; Esser, H.-J.. |
| The most recent phylogenetic analyses of the Malphigiales place the family Rafflesiaceae in the Euphorbiaceae, near the base of the clade. Combining both families is not an attractive option, because the Rafflesiaceae are very recognisable, while the Euphorbiaceae is one of the most polymorphic families around. The solution is to recognize the basal part of the Euphorbiaceae as Peraceae, which will leave the Rafflesiaceae and rest of the Euphorbiaceae untouched. The typical characters of the Peraceae are discussed. Within Malesia the family contains two genera, Chaetocarpus (1 species) and Trigonopleura (3 species). All species are mainly west Malesian taxa. They have as shared typical characters obovate stipules, united stamens and densely hairy fruits.... |
| Tipo: Article / Letter to the editor |
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| Ano: 2013 |
URL: http://www.repository.naturalis.nl/record/579376 |
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| Welzen, P.C. van. |
| A world-revision of Arthraxon Beauv. ( Gramineae) is presented. Three wide-spread species, A. hispidus (Thunb.) Makino, A. lanceolatus (Roxb.) Hochst., and A. lancifolius (Trin.) Hochst. are very variable and have caused the description of a great number of taxa, most of which are here reduced to synonomy. There are now 7 species and 9 varieties; for 6 of the latter new combinations are proposed. No new taxa are described. |
| Tipo: Article / Letter to the editor |
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| Ano: 1981 |
URL: http://www.repository.naturalis.nl/record/525125 |
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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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| Welzen, P.C. van. |
| Six species are recognized in Neoscortechinia, two more than before, because N. angustifolia is raised to species level and N. forbesii is split into N. philippinensis (new combination) and N. forbesii s.s. The varieties of N. kingii are united. The genus Cheilosa, which closely resembles Neoscortechinia, is kept separate and it is used as the outgroup in the cladistic analysis of Neoscortechinia. The latter analysis resulted into a cladogram, which shows a first branching off of the sister species N. angustifolia and N. sumatrensis, followed by a subsequent branching off of N. nicobarica, N. philippinensis, and finally N. forbesii and N. kingii. Four of the six species show a wide-spread distribution in W Malesia ( N. kingii, N. nicobarica, N.... |
| Tipo: Article / Letter to the editor |
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| Ano: 1994 |
URL: http://www.repository.naturalis.nl/record/525713 |
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| Welzen, P.C. van; Sierra, S.E.C.; Gebraad, M.J.H.; Kulju, K.K.M.. |
| Mallotus concinnus Airy Shaw, M. havilandii Airy Shaw, M. insularum (Airy Shaw) Slik, and M. miquelianus (Scheff.) Boerl. are very similar in appearance, with opposite leaves of which one large and elliptic, and the other reduced and more or less obcordate. However, a detailed look revealed enough differences to regard them as distinct species. |
| Tipo: Article / Letter to the editor |
Palavras-chave: Euphorbiaceae; Hancea; Mallotus. |
| Ano: 2006 |
URL: http://www.repository.naturalis.nl/record/525901 |
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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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| Chantarasuwan, B.; Peng, Y.-Q.; Baas, P.; Rasplus, J.-Y.; Heuven, B.-J. van; Welzen, P.C. van. |
| A small fig tree has been misidentified as Ficus orthoneura for a long time. However, morphologically it is distinct from F. orthoneura and F. hookeriana. Typical are the ellipsoid, puberulous receptacle and caducous basal bracts. Leaf anatomy shows a multiple epidermis with the cells in the inner layer much larger than in the outer layer and thus both layers resemble an epidermis with a separate hypodermis. The abaxial cuticle is strongly sculptured, the palisade layer shows some long subdivided cells, and enlarged lithocysts are only present abaxially. Because of these differences we hereby describe it as a new species, named in honour of Cornelis (Cees) Berg: Ficus cornelisiana. |
| Tipo: Article / Letter to the editor |
Palavras-chave: China; Ficus; Moraceae; New species; Vietnam. |
| Ano: 2014 |
URL: http://www.repository.naturalis.nl/record/524854 |
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| Welzen, P.C. van; Forster, P.I.. |
| Formerly, the Picrodendraceae formed the subfamily Oldfieldioideae within the Euphorbiaceae. The introduction discusses the taxonomy, wood and pollen morphology. Only four genera are present in Malesia. Three of them are either monotypic (Kariothamnus) or comprise only a single species (Choriceras and Petalostigma) in New Guinea. Austrobuxus (three species) is the only widespread genus in Malesia. The taxonomic treatment contains descriptions, keys, drawings and notes on distribution, ecology, etc. |
| Tipo: Article / Letter to the editor |
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| Ano: 2011 |
URL: http://www.repository.naturalis.nl/record/579372 |
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| Registros recuperados: 60 | |
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