Aanwinsten voor de Nederlandse adventief-flora, 4

This paper contains acquisitions to the adventitious flora of the Netherlands, mainly from the year 1962. 1. Cerastium dichotomum L. (fig. 1, d), a native of the Mediterranean region and of W. Asia, was found at Oostmahorn, prov. Friesland, near a harbour made for the reclamation of the Lauwerszee. 2. Arabis rosea DC., most likely introduced in the dunes near Bloemendaal, prov. N. Holland, with pheasant-food. The species is indigenous in Central and S. Italy, and in Sardinia and Sicily. Differences between this species and the closely related A. muralis Bertol. are discussed. 3. Pavonia urens Cav. (fig. 1, a-c). The var. hirsuta (Hochst. ex Ulbr.) Brenan of this tropical African species was found as an alien near a wool-mill at Tilburg, prov. N. Brabant. 4. Allium atropurpureum Waldst. & Kit. from the northern part of the Balkan Peninsula, like Arabis rosea probably introduced with pheasant-food, was found in the dunes of the intake of the Amsterdam Waterworks near Vogelenzang, prov. N. Holland.