Consulta: creatorFacets:"Welzen, P.C. van"
Registros recuperados: 60
Data/hora: 09/06/2024 10:20:11

A leaf anatomical contribution to the classification of the Linaceae complex
Provedor de dados: 16
Autores: 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
Ano: 1984
URL: http://www.repository.naturalis.nl/record/526014

Revision of the genus Cleidion (Euphorbiaceae) in Malesia
Provedor de dados: 16
Autores: Kulju, K.K.M.; Welzen, P.C. van.
A revision of the Malesian species in the genus Cleidion is presented. Cleidion javanicum is shown to be the correct name for the widespread type species (instead of the name C. spiciflorum). A new species, C. luziae, resembling C. javanicum, is described from the Moluccas, New Guinea and the Solomon Islands. In addition, C. salomonis is synonymised with C. papuanum and C. lanceolatum is treated as a variety of C. ramosii. In total 7 Malesian Cleidion species are recognized. Cleidion megistophyllum from the Philippines cannot reliably be confirmed to belong to the genus due to lack of information and specimens and is treated as a doubtful species.
Tipo: Article / Letter to the editor
Palavras-chave: Cleidion; Acalypheae; Cleidiinae; Revision; Taxonomy; Malesia.
Ano: 2005
URL: http://www.repository.naturalis.nl/record/524437

A taxonomic revision of the genus Arthraxon Beauv. (Gramineae)
Provedor de dados: 16
Autores: 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
Ano: 1981
URL: http://www.repository.naturalis.nl/record/525125

Taxonomy, phylogeny, and geography of Neoscortechinia Hook. f. ex Pax (Euphorbiaceae)
Provedor de dados: 16
Autores: 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
Ano: 1994
URL: http://www.repository.naturalis.nl/record/525713

Revision of the Malesian species of Dimorphocalyx (Euphorbiaceae)
Provedor de dados: 16
Autores: Welzen, P.C. van; Oostrum, A.F. van.
Dimorphocalyx, a small genus ranging from Sri Lanka to Indomalesia to Australia, has eight species in Malesia, of which one is here raised from variety to species level and another, endemic in the N Moluccas, is newly described. Dimorphocalyx murinus and – tentatively – D. loheri are synonymised with D. denticulatus, and D. luzoniensis is synonymised with D. malayanus. Dimorphocalyx cumingii is regarded as a species of Trigonostemon. The differences between Dimorphocalyx, Ostodes, Paracroton (formerly Fahrenheitia), and Trigonostemon are discussed.
Tipo: Article / Letter to the editor
Palavras-chave: Dimorphocalyx; Euphorbiaceae; Malesia; Ostodes; Paracroton; Trigonostemon.
Ano: 2015
URL: http://www.repository.naturalis.nl/record/578366

The distinction of five Mallotus species formerly in section Hancea (Euphorbiaceae)
Provedor de dados: 16
Autores: 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

A taxonomic revision of Trigonostemon (Euphorbiaceae) in Malesia
Provedor de dados: 16
Autores: Yu, R.-Y.; Welzen, P.C. van.
Trigonostemon is taxonomically revised for Malesia based on herbarium collections and field observations. Thirty-eight species are recognized in Malesia, of which four of uncertain status and four newly described. The previous infrageneric classifications are briefly reviewed, but none is accepted. Some useful characters are discussed. An identification key, nomenclature, descriptions, typification, geographic distributions and taxonomic notes are provided.
Tipo: Article / Letter to the editor
Palavras-chave: Euphorbiaceae; Malesia; Morphological revision; Taxonomy; Trigonostemon.
Ano: 2018
URL: http://www.repository.naturalis.nl/record/643352

Bischofia and Hymenocardia (Phyllanthaceae) in Malesia
Provedor de dados: 16
Autores: Welzen, P.C. van.
The genera Bischofia and Hymenocardia both have a single species in Malesia. The two genera were always difficult to classify, both once formed their own family, but are now firmly embedded in the Phyllanthaceae. Of both genera a more complete nomenclature and biogeography is presented.
Tipo: Article / Letter to the editor
Palavras-chave: Bischofia; Euphorbiaceae; Hymenocardia; Malesia; Phyllanthaceae.
Ano: 2016
URL: http://www.repository.naturalis.nl/record/620942

Nineteen new species and a new combination in Guioa Cav. (Sapindaceae)
Provedor de dados: 16
Autores: Welzen, P.C. van.
Nineteen new species and one new infraspecific name are proposed for the genus Guioa Cav. (Sapindaceae). If available, a leaflet, a petal (inside view), and a fruit were depicted.
Tipo: Article / Letter to the editor
Ano: 1988
URL: http://www.repository.naturalis.nl/record/525036

Patterns in species richness and composition of plant families in the Malay Archipelago
Provedor de dados: 16
Autores: 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

Resurrection of Hancea and lectotypification of Adisca (Euphorbiaceae)
Provedor de dados: 16
Autores: Sierra, S.E.C.; Kulju, K.K.M.; Veldkamp, J.F.; Welzen, P.C. van.
Based on phylogenetic studies with DNA sequence data, the formerly monotypic genus Cordemoya was recently expanded with 16 additional species previously assigned to Mallotus. However, the earliest legitimate generic name available is Hancea, and, therefore, Cordemoya is here reduced to Hancea (20 new combinations are proposed). Subsequently, the subgenus and section Diplochlamys from Asia are renamed to Hancea. Additionally, the genus Adisca is lectotypified with Adisca floribundus (= Mallotus floribundus).
Tipo: Article / Letter to the editor
Palavras-chave: Euphorbiaceae; Adisca; Cordemoya; Diplochlamys; Hancea; Mallotus; Madagascar; Malesia; Mascarenes.
Ano: 2007
URL: http://www.repository.naturalis.nl/record/525717

Distribution maps of Pacific plants
Provedor de dados: 16
Autores: 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
Ano: 1993
URL: http://www.repository.naturalis.nl/record/509475

A revision of the Malesian species of Blachia (Euphorbiaceae)
Provedor de dados: 16
Autores: 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

Phylogenetic reconstruction prompts taxonomic changes in Sauropus, Synostemon and Breynia (Phyllanthaceae tribe Phyllantheae)
Provedor de dados: 16
Autores: Welzen, P.C. van; Pruesapan, K.; Telford, I.R.H.; Esser, H.-J.; Bruhl, J.J.
Previous molecular phylogenetic studies indicated expansion of Breynia with inclusion of Sauropus s.str. (excluding Synostemon). The present study adds qualitative and quantitative morphological characters to molecular data to find more resolution and/or higher support for the subgroups within Breynia s.lat. However, the results show that combined molecular and morphological characters provide limited synergy. Morphology confirms and makes the infrageneric groups recognisable within Breynia s.lat. The status of the Sauropus androgynus complex is discussed. Nomenclatural changes of Sauropus species to Breynia are formalised. The genus Synostemon is reinstated.
Tipo: Article / Letter to the editor
Palavras-chave: Breynia; Molecular phylogeny; Morphology; Phyllanthaceae; Sauropus; Synostemon.
Ano: 2014
URL: http://www.repository.naturalis.nl/record/525483

A revision of the genus Dysolobium (Papilionaceae) and the transfer of subgenus Dolichovigna to Vigna
Provedor de dados: 16
Autores: 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
Ano: 1985
URL: http://www.repository.naturalis.nl/record/526009

Revision of the genera Aleurites, Reutealis and Vernicia (Euphorbiaceae)
Provedor de dados: 16
Autores: Stuppy, W.; Welzen, P.C. van; Klinratana, P.; Posa, M.C.T.
The three closely related genera Aleurites J. R. Forst. &amp; G. Forst., Reutealis Airy Shaw and Vernicia Lour., together constituting the subtribe Aleuritinae of the tribe Aleuritideae (Euphorbiaceae subfamily Crotonoideae), are revised. Originally included in Aleurites, Reutealis and Vernicia are considered generically distinct on account of differences in the indumentum, leaf base, inflorescences, number of stamens and fruit type. This distinction has also been confirmed by a recent phylogenetic analysis. Aleurites (2 species) differs from Reutealis and Vernicia by the more numerous stamens arranged in 4 rather than in 2 whorls, and the indehiscent fruits. The monotypic genus Reutealis can easily be distinguished from Aleurites and Vernicia by its...
Tipo: Article / Letter to the editor
Palavras-chave: Aleurites; Reutealis; Vernicia; Malesia; Systematics; Taxonomy.
Ano: 1999
URL: http://www.repository.naturalis.nl/record/524645

How to tackle revisions of large genera: lessons from Macaranga and Mallotus (Euphorbiaceae)
Provedor de dados: 16
Autores: Welzen, P.C. van; Kulju, K.K.M.; Sierra, S.E.C.
Two approaches to revise large genera are discussed. The first approach can be done by a single person, who revises the genus area after area. The other approach is by a team that revises per infrageneric taxon (preferably a single person per infrageneric group). The two approaches have their positive and negative sides, but both give good results. One problem with both approaches is to keep an overview of a possible infrageneric classification. The latter problem can be tackled by performing phylogenetic analyses based on molecular markers (providing core phylogeny) in combination with morphological, palynological, and anatomical data (providing apomorphies for infrageneric taxa).
Tipo: Article / Letter to the editor
Palavras-chave: Euphoriaceae; Macaranga; Mallotus; Phylogeny; Revision; Species rich genera.
Ano: 2009
URL: http://www.repository.naturalis.nl/record/524736

Ficus cornelisiana, a new species of Ficus subsection Urostigma (Moraceae) from the Sino-himalayan region
Provedor de dados: 16
Autores: 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

Pandaceae
Provedor de dados: 16
Autores: Welzen, P.C. van.
Pandaceae is a monophyletic group of three genera that was often regarded as part of the Euphorbiaceae, but of which molecular based phylogenies show it to be a distinct family. Malesia comprises two genera, Galearia (five species) and Microdesmis (two species) of which the taxonomic status, wood and pollen is discussed in a general way. The genus and species treatments contain descriptions, drawings, keys, distribution maps, and notes on habitat, ecology, uses, etc.
Tipo: Article / Letter to the editor
Ano: 2011
URL: http://www.repository.naturalis.nl/record/579371

A revision of Jatropha (Euphorbiaceae) in Malesia
Provedor de dados: 16
Autores: 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

Key to the Malesian species of Mallotus (Euphorbiaceae)
Provedor de dados: 16
Autores: Welzen, P.C. van; Kulju, K.K.M.; Sierra, S.E.C.; Slik, J.W.F.
An identification key to all Malesian species of Mallotus was still lacking. So far, only keys per section of Mallotus or keys per island were generated. This is the first attempt to create a key for all species of Mallotus in Malesia.
Tipo: Article / Letter to the editor
Palavras-chave: Euphorbiaceae; Identification key; Malesia; Mallotus.
Ano: 2010
URL: http://www.repository.naturalis.nl/record/524703

The demarcation and internal division of Flora Malesiana: 1857 – present
Provedor de dados: 16
Autores: Raes, N.; Welzen, P.C. van.
Tipo: Article / Letter to the editor
Ano: 2009
URL: http://www.repository.naturalis.nl/record/525063

Re-shaping Mallotus [Part 1]: Expanded circumscription and revision of the genus Cordemoya (Euphorbiaceae)
Provedor de dados: 16
Autores: Sierra, S.E.C.; Aparicio, M.; Kulju, K.K.M.; Fišer, Ž.; Welzen, P.C. van; Ham, R.W.J.M. van der.
A recent phylogenetic study based on DNA sequence data detected a well-supported clade of a number of Mallotus species together with the genus Cordemoya. This clade is distinct from the large Mallotus s.s. clade. In this paper, Cordemoya (formerly monotypic with C. integrifolia from the Mascarene Islands) is expanded with sixteen additional species previously assigned to Mallotus. Taxa transferred to Cordemoya are: Mallotus sections Hancea and Oliganthae from Asia and M. baillonianus, M. capuronii, and M. spinulosus from Madagascar. The genus Cordemoya can be distinguished from Mallotus s.s. by the presence of pollen with areolate ornamentation with scabrae (perforate/microreticulate ornamentation with scabrae in the sample of Mallotus s.s. studied up to...
Tipo: Article / Letter to the editor
Palavras-chave: Euphorbiaceae; Cordemoya; Deuteromallotus; Mallotus; Malesia; Madagascar; Mauritius; Réunion.
Ano: 2006
URL: http://www.repository.naturalis.nl/record/525161

The Malesian species of Sarcopteryx Radlk. (Sapindaceae)
Provedor de dados: 16
Autores: Welzen, P.C. van.
The Malesian species of the genus Sarcopteryx are revised. Seven species are recognized, of which two, Sarcopteryx crispata and especially S. squamosa are very variable. Three new species are described: Sarcopteryx caudata, S. crispata, and S. rubiginosa.
Tipo: Article / Letter to the editor
Ano: 1991
URL: http://www.repository.naturalis.nl/record/525526

Peraceae
Provedor de dados: 16
Autores: 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
Ano: 2013
URL: http://www.repository.naturalis.nl/record/579376

A taxonomic revision of Mallotus section Mallotus (Euphorbiaceae) in Malesia
Provedor de dados: 16
Autores: Sierra, S.E.C.; Welzen, P.C. van.
A revision of Mallotus section Mallotus in Malesia is given. Descriptions, distribution maps, habit drawings and a key to all species are provided. The diagnostic characters for the section are briefly discussed. Four species (M. barbatus, M. macrostachyus, M. mollissimus, M. paniculatus) and one variety (M. paniculatus var. formosanus) are recognised.
Tipo: Article / Letter to the editor
Palavras-chave: Euphorbiaceae; Rottlerinae; Mallotus; Malesia; Taxonomy.
Ano: 2005
URL: http://www.repository.naturalis.nl/record/525832

The morphological range in Mallotus (Euphorbiaceae) and a taxonomic revision of its section Rottleropsis (including Axenfeldia) in Malesia, Thailand and Africa .
Provedor de dados: 16
Autores: 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

A taxonomic revision of Mallotus sections Hancea and Stylanthus (Euphorbiaceae)
Provedor de dados: 16
Autores: 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

The Mallotus wrayi complex (Euphorbiaceae)
Provedor de dados: 16
Autores: Welzen, P.C. van; Sierra, S.E.C.
The Mallotus wrayi King ex Hook.f. complex on the Sunda Shelf of the Malay Archipelago (Malay Peninsula, Sumatra, Java, Borneo) appeared to comprise four species instead of a single, very heterogeneous one. Two synonyms (M. caudatus Merr. and M. lancifolius Hook.f.) are resurrected and a new species, M. spinifructus, is described. Important characters can be found in the density of the hairs (glandular scale-like, simple or stellate), type of stellately bundled hairs, lengths of inflorescences, bracts, and bracts of the terminal bud, and in the stigma width and hairiness.
Tipo: Article / Letter to the editor
Palavras-chave: Euphorbiaceae; Mallotus; Sunda Shelf; Malesia.
Ano: 2006
URL: http://www.repository.naturalis.nl/record/524771

On the 80th birthdays of Willem J.J.O. de Wilde and Brigitta E.E. Duyfjes
Provedor de dados: 16
Autores: Baas, P.; Veldkamp, J.F.; Welzen, P.C. van.
Tipo: Article / Letter to the editor
Palavras-chave: Wilde; J.J.O. de Duyfjes; Brigitta E.E.
Ano: 2016
URL: http://www.repository.naturalis.nl/record/611431

In memoriam Cees Berg (2 July 1934 – 31 August 2012)
Provedor de dados: 16
Autores: Welzen, P.C. van; Gadella, T.W.J.; Maas, P.J.M.; Daly, D.C.; Mori, S.A.; Jørgensen, P.M.; Obermüller, F.A.; Kjellberg, F.; Rønsted, N.; Chantarasuwan, B.; Lut, C.W.J.
Tipo: Article / Letter to the editor
Ano: 2012
URL: http://www.repository.naturalis.nl/record/525008

A revision of Ostodes (Euphorbiaceae) in Malesia
Provedor de dados: 16
Autores: 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

Lepidopetalum Blume (Sapindaceae): taxonomy, phylogeny, and historical biogeography
Provedor de dados: 16
Autores: Welzen, P.C. van; Piskaut, P.; Windadri, F.I.
The genus Lepidopetalum Blume (Sapindaceae) contains 6 species, of which one, L. fructoglabrum, is newly described. Four species are found on New Guinea of which one also occurs in Australia, one on the Nicobar Islands and Sumatra and one on the Philippines. Specimens from Java, Sulawesi, the Moluccas, and the Lesser Sunda Islands could not be identified due to the lack of mature fruits.  The genus is characterized by typical domatia (hair tufts), petals (small, triangular with much larger, usually united scales), and fruits (flat, usually 2-locular, sarcotesta present). Important specific characters are the pilosity of the upper part of the pedicel, the shape of the disc, the type of hairs inside the fruit, and the type of sarcotesta.  A putative...
Tipo: Article / Letter to the editor
Ano: 1992
URL: http://www.repository.naturalis.nl/record/524660

Key to the Malesian genera of Sapindaceae (based on vegetative and fruit characteristics)
Provedor de dados: 16
Autores: Welzen, P.C. van.
A key to the 40 Malesian genera of Sapindaceae is provided. This key is only meant for fruiting specimens. As a first quick check of the correctness of the identification, short indications of the geography of the genera and, when present, figures of the fruits are provided.
Tipo: Article / Letter to the editor
Ano: 1988
URL: http://www.repository.naturalis.nl/record/524627

Mallotus kongkandae (Euphorbiaceae): new record for China
Provedor de dados: 16
Autores: Sierra, S.E.C.; Welzen, P.C. van.
Mallotus kongkandae Welzen &amp; Phattar. was thought to be endemic to Thailand, but it also occurs in China, though known under other names. The new list of synonyms, a distribution map, notes on habitat and ecology, and collector details are included.
Tipo: Article / Letter to the editor
Ano: 2006
URL: http://www.repository.naturalis.nl/record/524879

Reviews
Provedor de dados: 16
Autores: Duistermaat, Helena; Balgooy, M.M.J. van; Welzen, P.C. van; Esser, H.-J.; Middleton, David; Adema, Frits; Veldkamp, J.F.
The International Conference ‘Compositae: Systematics, Biology, Utilization’ held in 1994 inspired the authors, on the suggestion of Dr. K. Ferguson, to publish a book accommodating more general systematic papers on Asteraceae, resulting in the present work. It contains seventeen chapters [in English, French (1), and Spanish (1)], including the Introduction by C. Jeffrey, and is provided with a taxonomic index. Following the Introduction, Jeffrey gives a review of the developments in Asteraceae systematics during the last 20 years, since the conference of 1975. I agree with him that improvements are possible in the use of cladistic analysis in taxonomy, but it seems to me that his review is a bit too negative in this respect. Advances in Compositae...
Tipo: Article / Letter to the editor
Ano: 1997
URL: http://www.repository.naturalis.nl/record/525946

A taxonomic revision of Mallotus section Philippinenses (former section Rottlera – Euphorbiaceae) in Malesia and Thailand
Provedor de dados: 16
Autores: 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

Picrodendraceae
Provedor de dados: 16
Autores: 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
Ano: 2011
URL: http://www.repository.naturalis.nl/record/579372

Reduction of Breynia subgenus Hemisauropus to B. section Cryptogynium and discussion of the B. quadrangularis complex (Phyllanthaceae)
Provedor de dados: 16
Autores: Welzen, P.C. van.
Breynia subgenus Hemisauropus is reduced to Breynia section Cryptogynium. Arguments are given to regard the Breynia quadrangularis complex as a single species.
Tipo: Article / Letter to the editor
Palavras-chave: Breynia section Cryptogynium; Breynia quadrangularis complex; Euphorbiaceae; Phyllanthaceae; Sauropus.
Ano: 2017
URL: http://www.repository.naturalis.nl/record/630812

A taxonomic revision of Mallotus section Polyadenii (Euphorbiaceae)
Provedor de dados: 16
Autores: Bollendorff, S.M.; Welzen, P.C. van; Slik, J.W.F.
Mallotus sect. Polyadenii comprises eight species. It includes the former genus Coccoceras. Mallotus leucodermis var. puberulus, endemic to the Solomon Islands, is recognised on the species level as M. puber. Mallotus anisopodus, from Indochina, is synonymised with M. plicatus from Myanmar. The identification of species is difficult, especially of M. leucodermis and M. muticus. The two species are partly sympatric and only pistillate flowers or fruits provide reliable characters; specimens with staminate flowers are very difficult to identify.
Tipo: Article / Letter to the editor
Palavras-chave: Coccoceras; Mallotus; Malesia; Phylogeny.
Ano: 2000
URL: http://www.repository.naturalis.nl/record/525643

Subgeneric delimitation of the plant genus Phyllanthus (Phyllanthaceae)
Provedor de dados: 16
Autores: 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

Revision of the Malesian and Thai species of Sauropus (Euphorbiaceae: Phyllanthoideae)
Provedor de dados: 16
Autores: 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

Gloeocarpus Radlk. (Sapindaceae) revised
Provedor de dados: 16
Autores: Welzen, P.C. van.
In this article a short discussion is given about the position of the genus Gloeocarpus Radlk. (Sapindaceae) within the Cupanieae, as well as a description of the genus and its species G. patentivalvis (Radlk.) Radlk.
Tipo: Article / Letter to the editor
Ano: 1991
URL: http://www.repository.naturalis.nl/record/525949

A revision of the Malesian genus Blumeodendron (Euphorbiaceae)
Provedor de dados: 16
Autores: 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

Revision of Dicoelia (Phyllanthaceae; Euphorbiaceae s.l.)
Provedor de dados: 16
Autores: 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

Reviews
Provedor de dados: 16
Autores: 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
Ano: 1996
URL: http://www.repository.naturalis.nl/record/525707

The genus Mastersia (Papilionaceae: Phaseoleae)
Provedor de dados: 16
Autores: 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
Ano: 1984
URL: http://www.repository.naturalis.nl/record/525542

On Max van Balgooy’s 80th birthday
Provedor de dados: 16
Autores: Baas, P.; Roos, M.C.; Welzen, P.C. van.
Tipo: Article / Letter to the editor
Ano: 2012
URL: http://www.repository.naturalis.nl/record/524451

The genus Baliospermum (Euphorbiaceae) in Malesia
Provedor de dados: 16
Autores: Welzen, P.C. van.
The genus Baliospermum is revised for the Malesian area. A single, variable species is recognized: B. solanifolium.
Tipo: Article / Letter to the editor
Palavras-chave: Baliospermum; Euphorbiaceae; Malesia; Revision.
Ano: 2018
URL: http://www.repository.naturalis.nl/record/660278

Re-shaping Mallotus [Part 2]: inclusion of Neotrewia, Octospermum and Trewia in Mallotus s.s. (Euphorbiaceae s.s.)
Provedor de dados: 16
Autores: 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

Derris solorioides (Fabaceae), a new limestone species with true-paniculate inflorescences from North-Central Thailand
Provedor de dados: 16
Autores: 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

Revision and phylogeny of Acalypha (Euphorbiaceae) in Malesia
Provedor de dados: 16
Autores: 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

Lasiococca brevipes (Euphorbiaceae): a new combination
Provedor de dados: 16
Autores: Welzen, P.C. van; Sierra, S.E.C.
Lasiococca brevipes (Merr.) Welzen &amp; S.E.C. Sierra is a new combination based on Mallotus brevipes Merr. The new combination replaces Lasiococca malaccensis Airy Shaw, which appears to be a later synonym. The species is very rare, but widespread and seemingly with a very disjunct distribution, found in Sumatra, the Philippines, Sulawesi, and the Lesser Sunda Islands.
Tipo: Article / Letter to the editor
Palavras-chave: Lasiococcus; Euphorbiaceae; Malesia; Philippines.
Ano: 2005
URL: http://www.repository.naturalis.nl/record/525725

Lbase the database system of the Rijksherbarium/Hortus Botanicus
Provedor de dados: 16
Autores: 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
Ano: 1992
URL: http://www.repository.naturalis.nl/record/533261

Sapindaceae
Provedor de dados: 16
Autores: 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

Reviews
Provedor de dados: 16
Autores: 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
Ano: 1999
URL: http://www.repository.naturalis.nl/record/525694

Guioa cav. (Sapindaceae): Taxonomy, phylogeny, and historical biogeography
Provedor de dados: 16
Autores: 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
Ano: 1989
URL: http://www.repository.naturalis.nl/record/508231

Revision of Annesijoa, Elateriospermum and the introduced species of Hevea in Malesia (Euphorbiaceae)
Provedor de dados: 16
Autores: Sam, Hoang Van; Welzen, P.C. van.
Annesijoa is an endemic monotypic genus from New Guinea with as single species A. novoguineensis. Elateriospermum is also monotypic (E. tapos) and found in West Malesia. The South American genus Hevea comprises about 10 species. One species (H. brasiliensis) is presently cultivated worldwide in plantations for its rubber and has become one of the major economic products of SE Asia. Two other species, H. guianensis and H. pauciflora are sometimes present in Malesian botanical gardens.
Tipo: Article / Letter to the editor
Palavras-chave: Euphorbiaceae; Annesijoa; Elateriospermum; Hevea; Malesia.
Ano: 2004
URL: http://www.repository.naturalis.nl/record/526280

Cnidoscolus (Euphorbiaceae) escaped in Malesia?
Provedor de dados: 16
Autores: Welzen, P.C. van; Fernández-Casas, F.J.
The genus Cnidoscolus, a species rich genus in the Americas, has been introduced in the Philippines. A cultivar of Cnidoscolus aconitifolius is used as vegetable and has been collected from gardens in Manila and Pasay City and two times near Cebu City. It cannot be excluded that it has escaped cultivation there, but the species does not appear to be invasive.
Tipo: Article / Letter to the editor
Palavras-chave: Cnidoscolus; Euphorbiaceae; Introduced species; Jatropha; Malesia; Revision.
Ano: 2017
URL: http://www.repository.naturalis.nl/record/627817

A revision of the genus Actephila (Phyllanthaceae) in the Malesian region
Provedor de dados: 16
Autores: 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