Polemonium, commonly called Jacob's ladder, is a genus of between 25 and 40 species of flowering plants in the family Polemoniaceae, native to cool temperate to arctic regions of the Northern Hemisphere. One species also occurs in the southern Andes in South America. Many of the species grow at high altitudes in mountains. Most of the uncertainty in the number of species relates to those in Eurasia, many of which have been synonymized with P. caeruleum in the past. Polemonium species are used as food plants by the larvae of some Lepidoptera species including Coleophora polemoniella.