Oceanic islands are of particular importance for the conservation of global diversity. Rare island plants with small population sizes and unique genetic patterns resulting from prolonged evolutionary isolation are usually extremely fragile. Therefore, research dedicated to conservation of these plants should consider threat factors, population structure and genetic diversity to enable the development of scientifically supported management programmes. In a recent study published in AoB PLANTS, Dias et al. performed a comprehensive population genetic study of Lactuca watsoniana, Azorean lettuce, unravelling genetic diversity patterns intrinsically related to geographical distances and barriers. Their study shows that genetic diversity levels in island plants can be relatively high even for rare plants.