''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 The Northern Hemisphere is the half of Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's Nort ...

. 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 caeruleum'', known as Jacob's-ladder or Greek valerian, is a hardy perennial flowering plant. The plant produces cup-shaped, blue or white flowers. It is native to temperate regions of Europe. Growth The plant usually reaches tall ...

''. ''Polemonium'' are perennial plants (rarely

annual plant An annual plant is a plant that completes its life cycle, from germination to the production of seeds, within one growing season, and then dies. The length of growing seasons and period in which they take place vary according to geographical ...

s) growing 10–120 cm tall with bright green

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

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 Lepidoptera ( ) is an order (biology), order of insects that includes butterfly, butterflies and moths (both are called lepidopterans). About 180,000 species of the Lepidoptera are described, in 126 Family (biology), families and 46 Taxonomic r ...

species including '' Coleophora polemoniella''.

Species

Kew's

Plants of the World Online Plants of the World Online (POWO) is an online database published by the Royal Botanic Gardens, Kew. It was launched in March 2017 with the ultimate aim being "to enable users to access information on all the world's known seed-bearing plants by ...

accepts 37 species. Many are locally known simply as "Jacob's ladder". *'' Polemonium acutiflorum'' – tall Jacob's ladder *''

Polemonium boreale ''Polemonium boreale'', the northern Jacob's-ladder or boreal Jacobs-ladder, is a plant native to the most of the high arctic. In Greenland it is found only in a small area on the east coast. It is not very common. The whole plant is pubescent, ...

'' – northern Jacob's ladder *'' Polemonium brandegeei'' – Brandegee's Jacob's ladder *''

'' – 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 ''Polemonium eddyense'' is a perennial wildflower species in the family Polemoniaceae with the common name Mount Eddy sky pilot. It is endemic to a small area around Mount Eddy, California. Description ''Polemonium eddyense'' is a small herb wit ...

'' – Mount Eddy Jacob's-ladder *'' Polemonium elegans'' – elegant Jacob's ladder *''

Polemonium elusum ''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 o ...

'' – elusive Jacob's-ladder *''

Polemonium eximium ''Polemonium eximium'', the skypilot or showy sky pilot, is a perennial plant in the phlox family (Polemoniaceae) that grows at high altitudes (mostly above ).Sierra Nevada Wildflowers, Elizabeth Horn, Mountain Press Publishing Co., , 1998, p. 12 ...

'' – sky pilot *'' Polemonium foliosissimum'' – towering Jacob's ladder *''

Polemonium glabrum ''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 o ...

'' *''

Polemonium grandiflorum ''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 o ...

'' *''

Polemonium hingganicum ''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 o ...

'' *''

Polemonium kiushianum ''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 o ...

'' *'' Polemonium majus'' *''

Polemonium mexicanum ''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 o ...

'' *''

Polemonium micranthum ''Polemonium micranthum'' is a species of flowering plant in the phlox family known by the common names annual polemonium or annual Jacob's-ladder. It is native to western North America from British Columbia to North Dakota to California as well ...

'' – annual polemonium *'' Polemonium nevadense'' – Nevada Jacob's ladder *'' Polemonium occidentale'' – western Jacob's ladder *'' Polemonium pauciflorum'' – few-flower Jacob's ladder *''

Polemonium pectinatum ''Polemonium pectinatum'' is a species of flowering plant in the phlox family known by the common names Washington Jacob's-ladder and Washington polemonium. It is endemic to the state of Washington in the United States, where it occurs in the C ...

'' – Washington Jacob's ladder *'' Polemonium pulchellum'' *''

Polemonium pulcherrimum ''Polemonium pulcherrimum'' is a species of flowering plant in the phlox family known by several common names, including beautiful Jacob's-ladder, showy Jacob's-ladder, and skunk-leaved polemonium. It is native to western North America from Al ...

'' – beautiful Jacob's ladder *'' Polemonium reptans'' – Jacob's ladder, Greek valerian *'' Polemonium sachalinense'' *'' Polemonium schizanthum'' *''

Polemonium schmidtii ''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 o ...

'' * ''Polemonium'' × ''speciosum'' *'' Polemonium sumushanense'' *'' Polemonium vanbruntiae'' – Vanbrunt's Jacob's ladder * ''Polemonium'' × ''victoris'' *'' Polemonium vilosissimum'' *''

Polemonium villosum ''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 o ...

'' *'' Polemonium viscosum'' – sticky polemonium *''

Polemonium yezoense ''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 o ...

References

Polemoniaceae genera {{Polemoniaceae-stub