The occurrence of Poa bulbosa var. bulbosa (non-proliferous form) on the island of Ameland is discussed. It was first observed there in 1973. Eighteen years later it has settled in 26 kilometer squares. It occurs only along paths and roads in the dune area. On Ameland, the distribution pattern shows three main areas, separated by major gaps. All three areas are frequented by tourists. The bulbs may adhere to clothing of man and thus be spread. Usually only small intervals are bridged, but sometimes the species may travel considerable distances. This way, the plant may suddenly appear at distant localities.