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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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| Heerden, Adrie van; Kerkhof, Dick. |
| Pilularia globulifera is restricted to Europe. It has a scattered distribution and in the most parts it is considered vulnerable or endangered. In the Netherlands it seemed confined to sandy or loamy soils in pleistocene and dune areas. In 1987, however, it was found in a ditch on acid clay (kattenklei) in the province of Zuid-Holland. This ditch is strongly influenced by seepage water. Relevées 2 and 3 show the vegetation of the margin of the ditch (nr. 2) and the ditch proper (nr. 3). In 1995 Pilularia was discovered near Berkenwoude in a former meadow of which the top layer (about 25 cm) was removed in 1994. Here it grew on peat in an area in which rainwater infiltrates. Relevée 1 was made on the latter locality. |
| Tipo: Article / Letter to the editor |
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| Ano: 1996 |
URL: http://www.repository.naturalis.nl/record/528016 |
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| Kerkhof, Dick. |
| In the Netherlands Elymus caninus was thought to be restricted to calcareous soils in Zuid- Limburg and the riverine area. However, since 1990 it has been recorded in fourteen 1 km-squares in the Vijfheerenlanden (a region in the province of Zuid-Holland) and adjacent Gelderland, growing in willow coppice and poplar-woods on non-calcareous clay-on-peat-soils in a low-lying, groundwater-fed area. The stands in which it occurs, resemble the Filipendulo-Alnetum and the Fraxino-Ulmetum alnetosum (see Table 1). |
| Tipo: Article / Letter to the editor |
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| Ano: 1998 |
URL: http://www.repository.naturalis.nl/record/526685 |
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