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| Registros recuperados: 60 | |
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| Welzen, P.C. van; Baas, P.. |
| The leaf anatomy of the Linaceae complex (Linaceae s.s., Hugoniaceae, Ixonanthaceae, Humiriaceae and Erythroxylaceae) and putative allies ( Ctenolophon, Lepidobotrys, Irvingiaceae) is surveyed, mostly on the basis of original observations (72 specimens, 27 genera), partly from data in the literature. Diversity in stomatal type, midrib and petiole vascularisation, sclerenchyma support, foliar sclereids, mucilage cells, secretory cavities, and cristarque cells provide evidence in favour of a separate family status of the members of the Linaceae complex. Allantospermum and Cyrillopsis are best accommodated in the Ixonanthaceae. Irvingiaceae (often treated in or near Simaroubaceae) show similarities with the Linaceae complex, albeit more closely to the... |
| Tipo: Article / Letter to the editor |
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| Ano: 1984 |
URL: http://www.repository.naturalis.nl/record/526014 |
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| Welzen, P.C. van; Sweet, F.S.T.; Fernández-Casas, F.J.. |
| Jatropha, a widespread, species rich genus, ranges from the Americas and Caribbean to Africa and India. In Malesia five species occur, all of which were introduced and originated in Central and South America. The five species are revised and an identification key, nomenclature, descriptions, distributions, ecology, vernacular names, uses and notes are provided. Special attention is given to the uses of J. curcas, because it is steadily gaining popularity as a potential biofuel plant and, because of that, is being cultivated more often. |
| Tipo: Article / Letter to the editor |
Palavras-chave: Euphorbiaceae; Introduced species; Invasive species; Jatropha; Malesia; Revision. |
| Ano: 2017 |
URL: http://www.repository.naturalis.nl/record/627810 |
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| Welzen, P.C. van; Winkel, E.. |
| The variability of Ostodes paniculata var. paniculata, the only representative of the genus in Malesia, is described. The variety and the species have a disjunct distribution as they are found in India to Southern China and the Southeast Asian mainland, Sumatra and Java. The variability in leaf glands, domatia, sepals, and seeds shows geoclines. Depending on one’s view the genus has two more varieties or species, both more hairy and occurring from N Thailand to China or in China only. Their nomenclature is provided, as is the nomenclature of the many excluded species, once part of a larger generic concept of Ostodes, but now mainly part of Dimorphocalyx and Paracroton. Typical for Ostodes are the red latex, the ovate, rather large serrate leaf blades with... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Dimorphocalyx; Euphorbiaceae; Malesia; Ostodes; Paracroton; Trigonostemon. |
| Ano: 2015 |
URL: http://www.repository.naturalis.nl/record/578359 |
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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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| Welzen, P.C. van; Hengst, S. den. |
| Dysolobium is a small legume genus, consisting of 4 species. It is closely related to Vigna, from which it differs by the shape of the wing petals and by the velvety, almost woody pods. Recently the genus has been divided into 2 subgenera, but in this paper the subgenus Dolichovigna is transferred back to Vigna. Possible relations between Dysolobium and genera as Vigna, Phaseolus, Canavalia, Dolichos, Psophocarpus, and Pueraria are discussed. Vigna seems to be the most closely related genus. Dysolobium is a Southeast Asian genus, two species of which are endemic and two more widespread; one of the latter ranges from India to Java (not extending more eastwards). The plants prefer a climate with a seasonal drought. Vigna pilosa is the only species in Vigna... |
| Tipo: Article / Letter to the editor |
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| Ano: 1985 |
URL: http://www.repository.naturalis.nl/record/526009 |
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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. |
| Malesia harbours one, possibly two species of Blachia. In the Philippines B. philippinensis is found and this species is not synonymous with B. andamanica. In literature B. andamanica has been recorded for west Malesia, but no specimens were seen. Based on its presence in Peninsular Thailand and the Andamans it is likely to be present in Peninsular Malaysia. The most distinct difference between both species is in the indumentum of the ovary, sparsely hairy in the lower half versus densely and completely sericeous, respectively. |
| Tipo: Article / Letter to the editor |
Palavras-chave: Blachia; Euphorbiaceae; Malesia. |
| Ano: 2015 |
URL: http://www.repository.naturalis.nl/record/578354 |
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| Sierra, S.E.C.; Welzen, P.C. van; Slik, J.W.F.. |
| A revision of Mallotus section Philippinenses (former section Rottlera) in Malesia and Thailand is given. Descriptions, distribution maps, habit drawings, and a key to the species are provided. The diagnostic characters for the section are briefly discussed. Five species (M. kongkandae, M. leptostachyus, M. pallidus, M. philippensis, and M. repandus) are recognised. Mallotus chromocarpus is excluded from the section because it has more shared characters with the monospecific genus Octospermum, like the presence of indehiscent fruits, absence of stipules, marginal extrafloral nectaries on the upper side of the leaf blade, broad connectives (shaped umbrella-like), and its occurrence in New Guinea, and is therefore probably closely related to it. |
| Tipo: Article / Letter to the editor |
Palavras-chave: Euphorbiaceae; Rottlerinae; Mallotus; Philippinenses; Rottlera; Octospermum; Malesia; Taxonomy. |
| Ano: 2005 |
URL: http://www.repository.naturalis.nl/record/525257 |
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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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| 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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| 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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| 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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| 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. |
| 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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| Registros recuperados: 60 | |
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