Veldwaarnemingen van Allium oleraceum L. (Moeslook) in het Beneden-IJsselgebied

Sixteen populations of Allium oleraceum were surveyed at its northern area border in the Netherlands. Unlike the situation in Central Europe most border populations were found on dikes in nutrient-rich heylands; the largest one, however, is situated in a woodland of the Violo-Ulmetum type. Clearing of woodland leads temporarely to an explosion of flowering specimens (Fig. 2). After the cold winter of 1996 the flowering period was delayed (Fig. 3). The number of flowers differs in each population, and is correlated with the plant length (Fig. 4). Table 1 presents data on the fertility (nbl = number of flowers, nfr = number of seeds). In the majority of the populations no seeds were produced, because of early mowing. Fig. 5 gives the results of a small experiment, comparing the germination of seeds with that of bulbils. Table 2 gives a survey of observed visiting insects, the most frequent among then are wasps.