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| Gradstein, S.R.; Hekking, W.H.A.. |
| This catalogue provides an annotated listing of the liverworts and hornworts from the Guianas (Guyana, Surinam, French Guiana), based on the literature and on new data that have become available in the framework of the “Flora of the Guianas” project. In total 375 species in 93 genera are recorded, including more than 100 species and 28 genera new to the Guianas. A list of synonyms (including 30 new ones), a systematic arrangement of the genera and families, and an index to the collectors are also given. |
| Tipo: Article / Letter to the editor |
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| Ano: 1985 |
URL: http://www.repository.naturalis.nl/record/535264 |
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| Gradstein, S.R.; Hekking, W.H.A.. |
| □ The main purpose of this catalogue is to provide a complete listing of the species of liverworts hitherto known from Colombia and to summarize our present knowledge of species distribution within the country. It was prepared parallel to a catalogue of the mosses (Musci), which is being published elsewhere (Florschütz & Waard in press). The data were extracted from the available literature and from unpublished determinations of collections from U and COL, made in Colombia by A.M. Cleef (Utrecht), T. van der Hammen (Amsterdam), H. Bischler (Paris) and others. While the first author is responsible for the taxonomy and nomenclature of the taxa, the second author is responsible for the data on species distribution and collecting. □ The literature on... |
| Tipo: Article / Letter to the editor |
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| Ano: 1979 |
URL: http://www.repository.naturalis.nl/record/534863 |
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| Hekking, W.H.A.. |
| There exist three different kinds of leaf arrangement in neotropical species of Rinorea. 1. an alternate leaf arrangement consisting of only laminar leaves; 2. an alternate leaf arrangement consisting of laminar leaves in the apical part of the branchlets and scale-like ones subpersistent in the basal part; 3. an apparently opposite leaf arrangement consisting of laminar leaves together with a pair of inconspicuous and soon deciduous scale-like leaves at the base of the inflorescences. In this article hypotheses have been constructed how one kind of leaf arrangement can be derived from the other, how these three different kinds of leaf arrangements can be correlated with the arrangements of the inflorescences and those of the branchlets, and finally how an... |
| Tipo: Article / Letter to the editor |
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| Ano: 1988 |
URL: http://www.repository.naturalis.nl/record/535273 |
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| Hekking, W.H.A.. |
| The neotropical genus Fusispermum (actinomorphous Violaceae) contains two species in northern South America (Peru, Colombia) and a third species F. laxiflorum Hekking sp. nov. from Panama. The genus differs from two subfamilies Violoideae and Leonoideae of the Violaceae as distinguished by Melchior, by its convolute aestivation of the petals, its deviating androecium and its capsula containing two different kinds of seeds and is therefore placed in a subfamily of its own, Fusispermoideae Hekking subfam. nov. A key to the neotropical actinomorphous genera of Violaceae is provided. |
| Tipo: Article / Letter to the editor |
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| Ano: 1983 |
URL: http://www.repository.naturalis.nl/record/535283 |
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| Hekking, W.H.A.. |
| Dans la région des dunes et des bas-fonds située à une distance de 3.6 à 5.3 kilomètres de Carnon au Grau du Roi, entre l’Etang de Mauguio et la Mer méditerranéenne et dans le département de l’Hérault on peut constater deux suites progressives des associations phytosociologiques : A) LA VÉGÉ TATION DES DUNES Plage: I. Agropyretum mediterraneum. ↓ Dunes: II. Ammophiletum arundinaceae (Tableau A). III. Crucianelletum maritimae (Tableau B et C). Dunes, un peu IIIa. sous-association: Helichrysetosum. stabilisées: IIIb. sous-association: Teucrietosum. ↓ (Mosaïque de IIIa et de IIIb: Tableau B). Dunes plus IIIc. sous-association: Ephedretosum (Tableau C). stabilisées: (parfois une végétation anormale et remplaçante d Holoschoenus vulgaris LINK. ssp. romanus (L.)... |
| Tipo: Article / Letter to the editor |
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| Ano: 1959 |
URL: http://www.repository.naturalis.nl/record/534886 |
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| Hekking, W.H.A.. |
| Herbs or shrubs. Leaves alternate or opposite, simple. Stipules present. Flowers actinomorphic or zygomorphic, usually hermaphroditic, rarely polygamous or cleistogamous. Sepals 5, usually free, persistent, imbricate. Petals 5, alternating with the sepals, usually free. Stamens usually 5, episepalous; filaments short; anthers usually introrse, more or less connivent, with or sometimes without connective-scales. Filaments short. Ovary superior, usually 3-celled with parietal placentas, each furnished with 1—∞ anatropous ovules; style one. Fruit capsular and loculicidal, bacciform or nuciform. Seeds with carnose endosperm; embryo straight. About 900 species in nearly 20 genera all over the world, especially in tropical and temperate regions. |
| Tipo: Article / Letter to the editor |
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| Ano: 1966 |
URL: http://www.repository.naturalis.nl/record/503207 |
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