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	Provedor de dados Naturalis (34) Autor Heel, W.A. van (34) Ham, R.W.J.M. van der (2) Wilde, W.J.J.O. de (2) Baas, P. (1) Bakhuizen van den Brink, R.C. (1) Balgooy, M.M.J. van (1) Bouman, F. (1) Breure, C.J. (1) Erbar, C. (1) Hovenkamp, P. (1) Jacobs, M. (1) Kalkman, C. (1) Leenhouts, P.W. (1) Leins, P. (1) Menendez, T. (1) Uffelen, G.A. van (1) Valkenburg, Johan L.C.H. van (1) Vermeulen, J.J. (1) Vink, W. (1) Welzen, P.C. van (1) Mais... Tipo do documento Article / Letter to the editor (34) Ano 1996 (1) 1994 (1) 1992 (1) 1990 (2) 1988 (2) 1987 (2) 1986 (1) 1984 (2) 1983 (1) 1982 (1) 1981 (1) 1979 (2) 1978 (1) 1977 (3) 1974 (1) 1973 (1) 1972 (2) 1971 (3) 1970 (1) 1967 (1) Mais... País Netherlands (34)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 34 Primeira ... 1 2 ... Última Morphology of the pistil in Malvaceae-Ureneae Naturalis Heel, W.A. van. The puzzling fact that the pistils of Malvaceae-Ureneae have five locules, but ten, instead of five, stylar branches, is made clear by a study of their development. Tipo: Article / Letter to the editor Ano: 1978 URL: http://www.repository.naturalis.nl/record/525944 Review Naturalis Heel, W.A. van. This book is an exploration into the field of Plant Morphology. It deals with the placentation of the ovules in ten families of Centrospermae — including the Cactaceae — and in the Primulaceae. The core is formed by a very close observation and a complete documentation of the histogenesis of the ovary wall, the septs, and the placentae in four Caryophyllaceous species. Furthermore, the result is compared with similar known and newly discovered features in other species and in the other families. It appears that the ovary is composed of a cup of sterile phyllomes which surrounds a central body. This central part is built up by two alternating sets of five axial placentae bearing the ovules. The septs grow from the cup inwards and fuse with the placentae and... Tipo: Article / Letter to the editor Ano: 1972 URL: http://www.repository.naturalis.nl/record/524706 The ascidiform early development of free carpels, a S.E.M.-investigation Naturalis Heel, W.A. van. Carpels develop centripetally as oblique slightly ascidiform structures provided with a seat-like support. The terminal mouth of the ascidiform primordium becomes the lateral cleft of the carpel. Solitary terminal carpels develop as lateral structures. The sections Tasmannia and Drimys of the genus Drimys differ by the varying degree of ascidiform development. Austrobaileya is like Drimys. The structure of the carpel margins with submarginal placentation may have evolved from a slit like that in Winteraceae. Allometric development of an oblique ascidiform structure may have formed a large basal ovary, and may thus have moved the stigmatic part apically. A possible cupular origin of carpels is discussed. Tipo: Article / Letter to the editor Ano: 1983 URL: http://www.repository.naturalis.nl/record/524669 Distally lobed integuments in some Angiosperm ovules Naturalis Heel, W.A. van. In this treatise ‘De l’Ovule’ Warming (1878) remarked that although the borders of the integuments grow uniformly, very rarely a division into lobes can be observed. He mentioned Symplocarpus foetida (inner integument four-lobed), Lagarosiphon schweinfurthii (outer integument four- or five-lobed) and Juglans regia (two-lobed). Moreover he cited the report by some authors of an occasional occurrence of lobed integuments in a few more plants. More recently Leroy (1955) described bilobed single integuments in Juglans and Platycarya. Boesewinkel and Bouman (1967) demonstrated that these lobes arise as two separate primordia in Pterocarya and Juglans. Tipo: Article / Letter to the editor Ano: 1970 URL: http://www.repository.naturalis.nl/record/525594 The pattern of vascular bundles in the stamens of Nymphaea lotus L. and its bearing on stamen morphology Naturalis Heel, W.A. van. In 1969 I published, together with P. G. Heinsbroek, a paper on the anatomy of the stamens of Victoria amazonica. The flowers used in that study came from plants which were cultivated in the green-house of the Leiden Botanic Garden. Because the possibility could not be excluded that the structures then observed were partly the effect of greenhouse conditions, I subsequently took the opportunity to study flowers of well developed plants, which were cultivated in the open air under the tropical conditions of the Botanic Garden at Bogor*). The results were exactly the same. Apart from the set of central vascular bundles, normal in laminar structures, there proved to be a peripheral sheath of bundles consisting of abaxial bundles, terminating half way up the... Tipo: Article / Letter to the editor Ano: 1977 URL: http://www.repository.naturalis.nl/record/524678 On the development of some Gynoecia with septal nectaries Naturalis Heel, W.A. van. Septal nectaries are formed by local regions of later nectariferous epidermal cells on the sides of the carpels at their very base. In order that the epidermal cells may differentiate into nectariferous cells, the carpels which constitute the gynoecium have to develop as separate organs. It was argued that if no septal nectaries develop, this free carpel development does not take place. The nectariferous regions get shaped as nectar containers by dermal fusion of the sides of the carpels surrounding them, by upward growth of the apex, and mostly also by meristematic continuity of part of the ovary wall on the outside. By the latter the level of the openings of the nectaries on the ovary is defined. Septal nectaries in Monocotyledons are considered original. Tipo: Article / Letter to the editor Ano: 1988 URL: http://www.repository.naturalis.nl/record/525402 Note on the morphology of the male inflorescences in Cercidiphyllum (Cercidiphyllaceae) Naturalis Heel, W.A. van. Male reproductive axes are described which have three pairs of decussate bracts, some with free axillary groups of stamens. The developmental stages are demonstrated by scanning electron microscopy (SEM). The view, earlier advanced for the female counterparts, that these reproductive axes are reduced polyaxial systems, is supported. Tipo: Article / Letter to the editor Ano: 1987 URL: http://www.repository.naturalis.nl/record/524939 Review Naturalis Heel, W.A. van. This book was composed after a manuscript left by W. Troll of his work Die Infloreszenzen II, part III, chapter 5, Fischer, Jena, 1969. Part I was published in 1964, part II in 1969. Weberling elaborated and updated this manuscript, describing examples of monotelic families, in the style of W. Troll. Together the three books – all wrapped in orange covers – represent a standard work consisting of more than 1700 pages and 1436 figures. The figures are combinations of photographs of living plants, explanatory drawings, and schemes. The drawings especially show good old handwork. Because 20-25 years after the first two volumes this third book will tend to lead its own life, Weberling has included a recapitulation of the principles of polytelic and monotelic... Tipo: Article / Letter to the editor Ano: 1990 URL: http://www.repository.naturalis.nl/record/525252 Review Naturalis Ham, R.W.J.M. van der; Heel, W.A. van. Secondary pollen presentation is a taxonomically widespread phenomenon that is unknown to many botanists. As defined by the author, it embraces those cases in which pollen is transferred within the flower, and presented to pollinators on or by floral structures other than the thecae. The intraflower transfer often involves intriguing adaptations of petals, androecium and distal parts of the gynoecium. The present book is largely a case of secondary presentation itself, being actually a review of the literature on the subject, supplemented with unpublished data and drawings. The main part (208 pp.) extensively describes familywise all taxa known to have secondary pollen presentation, with many comments inserted. Papaveraceae, Leguminosae, Proteaceae,... Tipo: Article / Letter to the editor Ano: 1994 URL: http://www.repository.naturalis.nl/record/525231 Flowers and fruits in Flacourtiaceae. II. The seeds of Pangium edule Reinw Naturalis Heel, W.A. van. The seeds are inferior. Only in the apical part of the seed the testa is integumental; for the greater part it is chalazal. A thick mesotesta is formed by a matted layer of sclereids. The chalazal part of the ectotesta is richly vascularized. A sheath of inverted vascular bundles occurs on the inside of the chalazal part of the mesotesta. The seeds are albuminous, the cotyledons foliaceous. An inside cavity may make the seeds float in water. The nucellar beak persists in the ripe seed. The endopyle is five-rayed in c.s., the ectopyle is a longitudinal slit. Tipo: Article / Letter to the editor Ano: 1974 URL: http://www.repository.naturalis.nl/record/524602 Reviews Naturalis Vink, W.; Leenhouts, P.W.; Balgooy, M.M.J. van; Hovenkamp, P.; Vermeulen, J.J.; Wilde, W.J.J.O. de; Heel, W.A. van. The Hamameli(i)dae comprise, according to the new classification by Thorne, about one quarter of the genera to one third of the families of the Dicotyledonae. The symposium held at the University of Reading, U.K, 22-25 March 1988, highlighted some of the many questions concerning phylogeny and evolution in this group as a contribution to the insight in the main lines of dicotyledonous evolution. The symposium report contains a wealth of information on a wide variety of topics. The phylogenetic position of the Hamamelidae in a wider or narrower sense, or parts thereof, is subject of a number of papers. F. EHRENDORFER reviews the existing diverging interpretations and concludes that the Hamamelidae can be regarded as ancient and partly relictual survivors... Tipo: Article / Letter to the editor Ano: 1990 URL: http://www.repository.naturalis.nl/record/525453 Note on some more tropical labyrinth-seeds Naturalis Heel, W.A. van. There are seeds that, when cut in any plane, show a labyrinth structure (van Heel, 1970). This may be due to folding of the cotyledons (Burseraceae, Dipterocarpaceae), or to the presence of testa tissue within the seed. In the latter case the testa tissue may either be located in the endosperm only (‘ruminated seeds’ in Palmae, Annonaceae, etc.), or the testa tissue may interfere with the cotyledons. It is possible that in some cases the testa at first interferes with the endosperm, and later on, when the embryo has become larger, also interferes with the cotyledons (Corner, 1966, in some Palmae). In the case of testa tissue interfering with the cotyledons, there are probably two possibilities. Firstly the testa may be located between portions of folded... Tipo: Article / Letter to the editor Ano: 1971 URL: http://www.repository.naturalis.nl/record/524652 Flowers and fruits in Flacourtiaceae. III. Some Oncobeae Naturalis Heel, W.A. van. Data are presented on Oncoba, Caloncoba, Camptostylus, Dasylepis, Scottellia, Berberidopsis, Lindackeria, and Peterodendron, with special emphasis on development and anatomy of the gynoecium. A neutral view is preferred to the carpel theory. There appears to be a link between parietal and basal placentation. It is proposed to refer to this placentation as cupular. Several peculiarities are found, such as ‘ramification’ of the stigmatic canals, penetration of the embryosac into the chalaza, distal lobes on integuments, separate vascular traces to the lowermost ovules, etc. Tipo: Article / Letter to the editor Ano: 1977 URL: http://www.repository.naturalis.nl/record/524458 A deviating female flower of Cercidiphyllum japonicum (Cercidiphyllaceae) Naturalis Heel, W.A. van. In one ‘flower’ a growing point occurred between a bract and its seemingly inverted carpel. Tipo: Article / Letter to the editor Ano: 1986 URL: http://www.repository.naturalis.nl/record/524974 On the morphology of the ovules in Salacca (Palmae) Naturalis Heel, W.A. van. Female inflorescences in several stages of development of Salacca edulis Reinw. were collected from stands in the Kebun Raya at Bogor and near the village Depok, West Java. In addition to this, material of S. wallichiana Mart. collected in the Kebun Raya, Bogor, was used in this morphological study*). Salacca belongs to the subfamily Lepidocaryoideae of Palmae, which is distinguished by its large fruit scales. As one of the results of the present study I could observe that the early development of these scales takes place in the epidermal cells of the young ovaries. The Lepidocaryoideae are furthermore distinguished by the position of their ovules. In Palms there is one axillary basal ovule in each locule. Usually the ovules are ascendent and anatropous,... Tipo: Article / Letter to the editor Ano: 1977 URL: http://www.repository.naturalis.nl/record/525764 Note on the floral development of Thottea (Aristolochiaceae) Naturalis Leins, P.; Erbar, C.; Heel, W.A. van. The occurrence of four placentae is a constant character in Thottea. The species can be distinguished by differences in the androecium. The androecial pattern is relatively variable and its rather high plasticity in the genus is suggested to be a derived feature within the family. The gynoecial structure is most remarkable, as the stylar organs do not correspond with the placentae in number nor in position. It is assumed that these organs do not belong to the gynoecium morphologically. They may represent independent, phylogenetically secondary organs, which may function in the capturing of pollen. Tipo: Article / Letter to the editor Ano: 1988 URL: http://www.repository.naturalis.nl/record/525710 The distally lobed inner integument of Hernandia peltata Meissn. in DC. (Hernandiaceae) Naturalis Heel, W.A. van. A peculiar structural detail, occurring during the development of ovules, seems to have passed almost unnoticed till the present day. It concerns the distal rim of either the outer or the inner integument, which appears to be slightly lobed in the ovules of several unrelated plants. In a recent note (1970) I called attention to this feature. It is known from Juglans and Platycaria (Warming, 1878; Leroy, 1955; Boesewinkel and Bouman, 1967), where the single integument is two-lobed. Warming mentioned two more cases, namely Lagarosiphon and Symplocarpus; however, I cannot confirm his observations from dried material. I noticed it myself in Scyphostegia horneensis, in Caloncoba welwitschii, and in Sterculia alexandri. In these three species the lobes occur at... Tipo: Article / Letter to the editor Ano: 1971 URL: http://www.repository.naturalis.nl/record/525683 Reviews Naturalis 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 Morphology at the Rijksherbarium Naturalis Heel, W.A. van. In the following the role of morphology, anatomy and palynology in systematics at the Rijksherbarium will be discussed, as far as flowering plants are concerned. It will be demonstrated that most of the research in this field is rooted in the interest of individual workers, and that no planning was involved until recently. The scope of it varied, as it was done either for pure taxonomic purposes, or for systematic and phylogenetic reasons, or for its own merit. Chiefly, I think, the study of morphology s.l. originated because Suringar, Hallier, Lotsy, and especially Lam, were interested in achieving a more natural or evolutionary system of the Angiosperms. Lotsy and Lam extended their interest to the other Cormophytes as well. In 1895 W. F. R. Suringar... Tipo: Article / Letter to the editor Ano: 1979 URL: http://www.repository.naturalis.nl/record/524558 Morphology of the androecium in Malvales Naturalis Heel, W.A. van. In order to test the applicability of the telome and the classic theories to the nature of stamens a study was made of flowers in Malvaceae, Bombacaceae, Sterculiaceae, Tiliaceae, and Elaeocarpaceae with respect to their ultimate form, their development, and the vascular course of their androecia. The customary dissecting, clearing, and microtomy techniques were used. A chapter on the interpretation of the vascular bundle course in floral morphology has been added. In each flower the stamens are considered to be arranged in five groups, which may be fused more or less laterally. The groups have a three-trace vascular system the laterals of which may be commissural. Only a few Tiliaceae have ten groups. Whereas in most Tiliaceae and Elaeocarpaceae the... Tipo: Article / Letter to the editor Ano: 1966 URL: http://www.repository.naturalis.nl/record/524954 Registros recuperados: 34 Primeira ... 1 2 ... Última

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