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| Registros recuperados: 16 | |
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| Baas, Wim J.; Duistermaat, Leni (H.). |
| The first local invasion of the alien subtropical aquatic Floating Pennywort (Hydrocotyle ranunculoides) in urban waterways during the hot summer of 1995 seemingly ended due to a combination of mechanical removal of floating and terrestrial plant material and a subsequent severe winter. Recently however the plant proved to be hardy to even severe frost when protected bij natural vegetation. As a result a large area of waterways in and around the city ’s-Hertogenbosch became covered with floating mats of plants which had to be removed at the expense of high costs. This however could not prevent the plant from escaping to the river Meuse, and probably from there to a former tidal nature reserve. Although the species will probably be confined to eutrophic... |
| Tipo: Article / Letter to the editor |
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| Ano: 1999 |
URL: http://www.repository.naturalis.nl/record/526988 |
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| Duistermaat, Leni (H.). |
| Bij het controleren van waarnemingen die aan FLORBASE zijn toegevoegd¹² bleek dat veel waarnemingen van Polygonatum odoratum (Welriekende salomonszegel) buiten het duingebied betrekking hebben op P. x hybridum (Tuinsalomonszegel). Polygonatum odoratum is een soort van droge, kalkrijke grond; hij is plaatselijk algemeen in het duingebied, daarbuiten zeer zeldzaam (o.a. op een paar plekken waar duinzand is aangevoerd). De genoemde hybride is het produkt van kruising tussen P. multiflorum (Gewone salomonszegel) en P. odoratum. De hybride is een forse, tot één meter hoge plant, die vanwege haar grootte geliefd is als tuinplant. Hij vormt zelden bessen, maar slaat echter gemakkelijk op uit wortelstokken die met tuinafval worden weggegooid en kan dan lang... |
| Tipo: Article / Letter to the editor |
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| Ano: 1999 |
URL: http://www.repository.naturalis.nl/record/526550 |
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| Duistermaat, Leni (H.). |
| Both Stachys recta and S. annua are considered adventive species in the Netherlands, and are therefore not included in the checklist of the Dutch flora.22 23 Recent records from the river valleys in the Eastern part of the country of the first species suggest that it is expanding its area into the Netherlands. Both fossile remains and (sub-)recent findings of S. annua indicate that deletion of this species from the 1990 version of the checklist is not justified.²³ |
| Tipo: Article / Letter to the editor |
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| Ano: 1996 |
URL: http://www.repository.naturalis.nl/record/527747 |
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| Meijden, Ruud van der; Holverda, Wout J.; Duistermaat, Leni (H.). |
| New indigenous species are Conopodium majus and Vulpia membranacea, and the recently recorded hybrid Scutellaria galericulata x minor (S. x hybrida). New and fully naturalized neophytes are the invasive species Hydrocotyle ranunculoides and Impatiens capensis. Other new neophytes are Anisanthamadritensis, Centaurea stoebe subsp. rhenana, Chenopodium ambrosioides, Crambe abyssinica, Dittrichia graveolens, Erigeron karvinskyanus, Koelreuteria paniculata, Malus baccata, Ornithopus compressus and Physalis peruviana. Anthericum liliago and Dianthus superbus were recorded again in the Netherlands after 80 years of disappearance, and Eleocharis ovata after 150 years. Bromus secalinus and Cuscuta gronovii are not yet extinct. Interesting new records of very rare... |
| Tipo: Article / Letter to the editor |
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| Ano: 1996 |
URL: http://www.repository.naturalis.nl/record/527403 |
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| Duistermaat, Leni (H.). |
| In de eerste warme stralen van de lentezon trokken de bewoners van Rommeldam in groepen naar het bos om te genieten van de violen die er bloeiden. Het waren werkelijk enige bloemen. Maar misbruik van violen leidt tot wortelroos en draadhippel in de bomen en dan gaat alles naar de verturving, zodat het duidelijk zal zijn dat alleen een goede determinatie hier redding brengt.¹² Het is echter niet gemakkelijk om de nauw aan elkaar verwante meerkleurige viooltjes te determineren, vooral omdat tussen Akkerviooltje ( V. arvensis) en Driekleurig viooltje ( V. tricolor) vruchtbare bastaarden gevormd worden. Beide zijn, tenminste in Nederland, eenjarige soorten, terwijl de andere twee soorten uit deze groep, Zinkviooltje (V. lutea subsp. calaminaria; blijft hier... |
| Tipo: Article / Letter to the editor |
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| Ano: 1999 |
URL: http://www.repository.naturalis.nl/record/528185 |
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| Meijden, Ruud van der; Holverda, Wout J.; Duistermaat, Leni (H.). |
| In the 20th century ca. 50 species disappeared; ca. 80 species became fully naturalized, 20% of which without any form of human interference. The greatest losses are among weeds and among species from nutrient poor, weakly acid habitats. Woodland species clearly increased, and the explosive urbanisation led to new niches for a number of species, even so that we now distinguish an “urban district” for plants. The present list contains a nice number of new records of very rare plants: Anacamptis pyramidalis, Apium repens, Blackstonia perfoliata s.s., Carex laevigata, Centaurea calcitrapa, Circaea alpina, Crepis foetida, Equisetum telmateia, Equisetum variegatum, Filago vulgaris, Huperzia selago, Hypericum canadense, Moneses uniflora. Totally new is Marsilea... |
| Tipo: Article / Letter to the editor |
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| Ano: 1999 |
URL: http://www.repository.naturalis.nl/record/527644 |
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| Kerkhof, Dick; Duistermaat, Leni (H.). |
| Leersia oryzoides has declined probably less dramatically than was assumed.² This freatophitic species is easily overlooked because its vegetative parts appear late in summer, and its inflorecences come out of the sheaths in warm summers only. In the region Vijfheerenlanden (province of Zuid-Holland) it is found in 29 kilometer squares in the period 1992—1994. Its occurrence seems to be related to the presence of bare places and steep banks of ditches with a southern exposition, as well as of seepage water. It is likely that its present distribution is larger than presented in Figure 1. |
| Tipo: Article / Letter to the editor |
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| Ano: 1995 |
URL: http://www.repository.naturalis.nl/record/527475 |
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| Duistermaat, Leni (H.). |
| FLORON is elf jaar geleden (in 1988) opgericht om verspreidingsgevens van de Nederlandse flora lands- en gebiedsdekkend te verzamelen, op te slaan en te beheren. Wij zetten daarmee het werk voort dat in 1902 door Goethart en Jongmans¹ is gestart, vanaf 1930 door het IVON (Instituut voor het vegetatieOnderzoek van Nederland), en later door het Rijksherbarium gecoördineerd. Het spreekt vanzelf dat wij graag veel gegevens bijeenbrengen. We zijn dan ook iedere winter weer verheugd dat er zoveel streeplijsten, Rode-Lijstformulieren en meldingskaartjes van floristen, doorgewinterde of beginnende, bij ons binnenkomen. Er zijn echter wel een aantal eisen waaraan een ingevuld formulier moet voldoen om gedigitaliseerd en in het FLORBASE-bestand opgenomen te kunnen... |
| Tipo: Article / Letter to the editor |
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| Ano: 1999 |
URL: http://www.repository.naturalis.nl/record/526748 |
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| Duistermaat, Leni (H.). |
| This year Falcaria vulgaris was found in the province of Limburg. It is predicted that the species will be fully naturalized in The Netherlands within a few years. Filago vulgaris was found on some new localities. The conditions in Noordwijk, between the pavement, are extraordinary. The rare casual Lythrum hyssopifolia was reported from the locality where it was already found in 1995. The population was still present in 1998, and flourishing: thousands of plants were seen. Juncus capitatus has been found on three new localities in 1998. In the eastern parts of the province of Noord-Brabant the localities are near the old, and now extinct localities. In the western part of this province its appearance is new. It is argued that seeds must have been living... |
| Tipo: Article / Letter to the editor |
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| Ano: 1998 |
URL: http://www.repository.naturalis.nl/record/527058 |
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| Meijden, Ruud van der; Holverda, Wout J.; Duistermaat, Leni (H.). |
| As a result of nature management measures a number of rare and endangered species reappeared, often after many decades of absence on the site: Apium inundatum, Anagallis tenella, Cicendia filiformis, Echinodorus repens, Eleocharis quinqueflora, Juncus tenageia, Ludwigia palustris, Myriophyllum alterniflorum, Pilularia globulifera and Viola persicifolia; the latest news (summer 1997) being the rediscovery of the presumably extinct Juncus capitatus. New are the alien species Nonea lutea, Salix udensis, and Typha minima. Field botanists are urged to collect more herbarium material and to improve the quality of their collections. |
| Tipo: Article / Letter to the editor |
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| Ano: 1997 |
URL: http://www.repository.naturalis.nl/record/527669 |
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| Schaminée, Joop H.J.; Duistermaat, Leni (H.); Veen, Wim de; Klinckenberg, Jan H.J.. |
| Oenanthe silaifolia was considered to be extinct in the Netherlands. The species was recorded for the last time in 1899, in a floodplain meadow near Rotterdam. Recently, the species has been found again – with only one individual – on a dike in the valley of the Maas near Stevensweert (central Limburg). The plant was growing in a ruderalized tall forb community, halfway on the dike, that could be classified as a basal community of Cirsium arvense of the class Artemisietea vulgaris. The stand was surrounded by herds of Phalaris arundinacea (along the foot of the dike) and hay meadow communities of the Arrhenatherion elatioris, the latter comprising some specific floodplain species like Ononis repens subsp. spinosa and Eryngium campestre. Most probably, the... |
| Tipo: Article / Letter to the editor |
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| Ano: 1999 |
URL: http://www.repository.naturalis.nl/record/526929 |
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| Slikke, Wout J. van der; Duistermaat, Leni (H.); Groen, Kees (C.) L.G.. |
| Between 1989 and 1993 the FLORON Foundation has run a special project to gather data on the distribution of 105 selected plant species in the Netherlands. More than 11.500 square kilometers were visited and a total amount of 150 thousand records has been accumulated by over 1200 botanical naturalists (here called florists). The distribution data have been added to the national floradatabase FLORBASE. The main result of the project is a large increase of our knowledge on the distribution patterns of the species involved, on a detailed scale of 1 x 1 km. The contribution to FLORBASE of known sites of these species due to this project varies between 15% and 69%. The increase is highest for early-flowering species and species that grow mainly at urban sites.... |
| Tipo: Article / Letter to the editor |
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| Ano: 1997 |
URL: http://www.repository.naturalis.nl/record/526536 |
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| Duistermaat, Leni (H.). |
| In 1998 werd melding gemaakt van een nieuwe Amarant voor de Nederlandse flora: Amaranthus bouchonii (Franse amarant).¹ Vanwege de wijdere verspreiding van dit nummer van Gorteria naar alle actieve FLORON-waarnemers is het zinvol nog even in te gaan op de herkenning van deze nieuwe soort. Amaranthus bouchonii (Franse amarant) lijkt waarschijnlijk al vele jaren in Nederland aanwezig te zijn, maar is al die tijd onopgemerkt gebleven en waarschijnlijk voor Amaranthus hybridus (Groene amarant) aangezien. Het belangrijkste verschil tussen de twee soorten, die wat habitus betreft sterk op elkaar gelijken, is dat de vrucht van A. bouchonii geen dekseltje heeft, terwijl die van A. hybridus wel een perforatielijn heeft waarlangs het bovenste gedeelte afbreekt (zie... |
| Tipo: Article / Letter to the editor |
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| Ano: 1999 |
URL: http://www.repository.naturalis.nl/record/527697 |
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| Registros recuperados: 16 | |
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