This paper contains acquisitions to the Netherlands adventitious flora from the year 1961. 1. Amaranthus palmeri S. Wats. This is the second species of the subgenus Acnida (L.) Aellen found in the Netherlands. The first species, A. tamariscinus Nutt. was found in 1953 as a wool-alien. In October 1961 both dioecious species were collected growing together along a roadside near Wageningen, introduced with corn. Differential characters between the two species are given and also a figure of a bract (fig. 1, a), an outer (fig. 1, b) and an inner tepal (fig. 1, c) of a female flower of A. palmeri. A. palmeri occurs in the southwestern United States and in Mexico. 2. Polygonum capitatum Hamilt. ex Don (fig. 1, d) was found in 1960 in a beet field between Wylre and Stokkum (prov. Limburg), where it has spread since. This species, a native of the Himalayas and the Khasia Hills is sometimes cultivated in botanical gardens. In what way it has come to the beet field is unknown. 3. Bidens polylepis Blake (fig. 1, e-f) originating from the central United States was found as an alien along a roadside between Oldenzaal and Denekamp (prov. Overijssel). 4. A number of plants escaped from cultivation.