Polemonium

''Polemonium'', commonly called Jacob's ladders or Jacob's-ladders (the name derived from the Biblical story), 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 mountainous areas. Most of the uncertainty in the number of species relates to those in Eurasia, many of which have been synonymized with ''Polemonium caeruleum''.

''Polemonium'' are perennial plants (rarely annual plants) growing 10–120 cm tall with bright green leaves divided into lance-shaped leaflets. They produce blue (rarely white or pink) flowers in the spring and summer.

Some species are used as food plants by the larvae of some Lepidoptera species including '' Coleophora polemoniella''.

Species

Kew's Plants of the World Online accepts 37 species. Many are locally known simply as "Jacob's ladder".

*'' Polemonium acutiflorum'' – tall Jacob's ladder
*'' Polemonium boreale'' – northern Jacob's ladder
*'' Polemonium brandegeei'' – Brandegee's Jacob's ladder
*''Polemonium caeruleum'' – Jacob's ladder (the original plant to bear this name); charity
*'' Polemonium californicum'' – showy Jacob's ladder
*'' Polemonium campanulatum''
*'' Polemonium carneum'' – royal Jacob's ladder
*'' Polemonium caucasicum''
*'' Polemonium chartaceum'' – Mason's Jacob's ladder
*'' Polemonium chinense''
*'' Polemonium confertum'' – Rocky Mountain Jacob's ladder
*''Polemonium eddyense'' – Mount Eddy Jacob's-ladder
*'' Polemonium elegans'' – elegant Jacob's ladder
*''Polemonium elusum'' – elusive Jacob's-ladder
*''Polemonium eximium'' – sky pilot
*'' Polemonium foliosissimum'' – towering Jacob's ladder
*''Polemonium glabrum''
*''Polemonium grandiflorum''
*''Polemonium hingganicum''
*'' Polemonium kiushianum''
*'' Polemonium majus''
*''Polemonium mexicanum''
*''Polemonium micranthum'' – annual polemonium
*'' Polemonium nevadense'' – Nevada Jacob's ladder
*'' Polemonium occidentale'' – western Jacob's ladder
*'' Polemonium pauciflorum'' – few-flower Jacob's ladder
*''Polemonium pectinatum'' – Washington Jacob's ladder
*''Polemonium pulchellum''
*''Polemonium pulcherrimum'' – beautiful Jacob's ladder
*'' Polemonium reptans'' – Jacob's ladder, Greek valerian
*''Polemonium sachalinense''
*'' Polemonium schizanthum''
*''Polemonium schmidtii''
* ''Polemonium'' × ''speciosum''
*''Polemonium sumushanense''
*'' Polemonium vanbruntiae'' – Vanbrunt's Jacob's ladder
* ''Polemonium'' × ''victoris''
*'' Polemonium vilosissimum''
*''Polemonium villosum''
*'' Polemonium viscosum'' – sticky polemonium
*''Polemonium yezoense''

References

Polemoniaceae genera

{{Polemoniaceae-stub