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| Registros recuperados: 38 | |
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| Gadella, Th.W.J.; Kliphuis, E.. |
| In the Netherlands two morphologically distinct groups of plants occur in the section Pilosellina of the genus Hieracium. The diploids and (very rarely occurring) triploids are restricted (as far as is known up till now) to the Isle of Terschelling and belong to the species Hieracium peleterianum Merat, whereas the tetra- and pentaploids belong to the species H. pilosella. This is the first record of Hieracium peleterianum for the Netherlands. |
| Tipo: Article / Letter to the editor |
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| Ano: 1968 |
URL: http://www.repository.naturalis.nl/record/528086 |
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| Gadella, Th.W.J.; Kliphuis, E.. |
| The present paper, the fifth¹) in this series, is a continuation of the documented list of chromosome numbers of Angiospermae occurring in the Netherlands. In this paper 49 species and two hybrids are listed. Some species show variation in chromosome number, as was concluded after comparison of our results with those of other authors [cf. the lists published by Löve and Löve (1961); Cave et al. (1956-1964); Ornduff (1967, 1968, 1969); Solbrig and Gadella (1970); Moore (1970)]. Some notes on 14 species and two hybrids are given. |
| Tipo: Article / Letter to the editor |
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| Ano: 1971 |
URL: http://www.repository.naturalis.nl/record/534685 |
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| Gadella, Th.W.J.; Kliphuis, E.; Mennega, E.A.. |
| In a previous paper (Gadella c.s. 1966) a list of chromosome numbers of flowering plants of S. France and Spain was published. Unfortunately, one of the plants was misidentified. Collection number 61, collected near Javea, Monte Mongo, Alicante (Spain), was incorrectly assigned to Cirsium acarna (L.) Moench. The plant was considered to be a Cirsium in view of the plumose pappus. The chromosome number of a number of plants grown from this seedsample turned out to be 2n = 22, a number not found earlier in any Eurasiatic species of Cirsium. Moore & Frankton (1963) studied several North American species of the genus Cirsium and pointed out that in the North American representatives of Cirsium the chromosome numbers 2n = 34, 32, 30, 28, 26, 24, 22, 20, 18... |
| Tipo: Article / Letter to the editor |
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| Ano: 1968 |
URL: http://www.repository.naturalis.nl/record/535059 |
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| Kliphuis, E.; Gadella, Th.W.J.; Dorrat-Haaksma, E.P.. |
| In Sweden Erlandsson (1942) showed that the species Parnassia palustris L. has two chromosome numbers, 2n = 18 and 2n = 36. Rozanova (1940) found the same numbers in plants collected in the U.S.S.R. Some morphological differences could be demonstrated in the Swedish material (Erlandsson, 1942). This was confirmed by Löve and Löve (1944) and, therefore, these authors (1950) distinguish 2 species: the diploid Parnassia palustris L. em. Löve and the tetraploid Parnassia obtusiflora Rupr. em. Löve, also separated by sterility barriers and by their geographical distribution. In the Netherlands a tetraploid population was found by Gadella and Kliphuis (1963). As the tetraploid population occurs in an area situated far south of the circumpolar distribution area... |
| Tipo: Article / Letter to the editor |
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| Ano: 1965 |
URL: http://www.repository.naturalis.nl/record/534811 |
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| Gadella, Th.W.J.. |
| Several species recorded in the Netherlands island of Schiermonnikoog are discussed. Cochlearia anglica L. found in the southern part of the island proved to be octoploid (2n = 48). The Netherlands material of 1 C. officinale L. ishexaploid (2n = 36) and cytologically and morphologically intermediate between the British C. officinale (tetraploid, 2n = 24) and C. anglica. The Ornithogalum umbellatum complex is represented by two taxa. Both the triploid O. umbellatum L. s.str. and the penta-/hexaploid O. divergens Bor. can be found near the village of Schiermqnnikoog; probably the plants are not indigenous there. Of Ranunculus ficaria L. only the subsp. bulbifer Lawalree was found. Stellaria graminea L. is mostly diploid (2n = 26) in the Netherlands and... |
| Tipo: Article / Letter to the editor |
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| Ano: 1983 |
URL: http://www.repository.naturalis.nl/record/527152 |
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| Gadella, Th.W.J.. |
| Previously, the chromosome numbers of some species of Loganiaceae were dealt with (Gadella, 1961, 1962, 1963). The chromosome numbers of 7 species are reported in this paper, of which 4 species, all belonging to the genus Strychnos, had not been investigated cytologically before. The materials, kindly supplied to me by Dr. A. J. M. Leeuwenberg and by Ir. F. Breteler, were collected in the form of seed-samples in the Ivory Coast and in Cameroun. The plants of 2 species originate from botanical gardens. Living material of all species (except for Strychnos lernata Gilg. ex Lwb.) is grown in the botanical garden of Wageningen (WAG). The determination of the chromosome numbers was based on the study of roottipmitoses. Roottips of the plants were fixed in... |
| Tipo: Article / Letter to the editor |
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| Ano: 1966 |
URL: http://www.repository.naturalis.nl/record/535107 |
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| Gadella, Th.W.J.. |
| The delimitation of genera in the Campanulaceae, especially in the subtribe Campanulinae, meets with serious difficulties. Linnaeus (1753, 1754) distinguished 3 genera: Campanula, Phyteuma, and Trachelium. In A. de Candolle’s (1830) monograph of the family 334 species were recognized, classed in 21 genera. Species of 12 of these genera had formerly been included in Campanula. Yet the genus Campanula still appears too inclusive, and the delimitation of some other genera is open to dispute. Not only the delimitation of genera presents serious difficulties, there is also no common opinion on the arrangement of the genera in tribes. The more important systems are those of Schönland (in Engler and Prantl, 1894) and of Fedorov (1957). Schönland arrived at the... |
| Tipo: Article / Letter to the editor |
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| Ano: 1966 |
URL: http://www.repository.naturalis.nl/record/534796 |
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| Kramer, K.U.; Westra, L.Y.Th.; Kliphuis, E.; Gadella, Th.W.J.. |
| In the spring of 1968 and 1969 the two senior authors visited the Maltese Islands of Malta and Gozo and collected and photographed plants. The entire herbarium collection amounts to about 350 numbers. The first set is deposited in the herbarium of the State University of Utrecht; duplicates were sent chiefly to the herbarium of the Royal Botanic Gardens, Edinburgh. Critical determination of the material yielded some results which may be interesting from a floristictaxonomic viewpoint and are therefore reported below. Beside herbarium material fruits and seeds were collected; the samples that germinated were investigated cytotaxonomically by the two junior authors. The results are also presented in the following. The first truly comprehensive account of the... |
| Tipo: Article / Letter to the editor |
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| Ano: 1972 |
URL: http://www.repository.naturalis.nl/record/535096 |
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| Gadella, Th.W.J.; Kliphuis, E.. |
| Crossing experiments were carried out between the three cytotypes (2n=24, 2n=40 and 2n=48) of Symphytum officinale and that of Symphytum asperum (2n=32), The results indicate that morphologically closely related types are sometimes crossable, whereas in other cases no hybrids could be produced. On the other hand morphologically very distinct types could be crossed with great ease. The significance of these studies for the elucidation of taxonomic problems is discussed. |
| Tipo: Article / Letter to the editor |
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| Ano: 1969 |
URL: http://www.repository.naturalis.nl/record/535024 |
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| Registros recuperados: 38 | |
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