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.[1][2] One species, Polemonium micranthum, 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.[3]

Polemonium
Polemonium reptans
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Ericales
Family: Polemoniaceae
Genus: Polemonium
L.
Type species
Polemonium caeruleum
L.

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

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Polemonium caeruleum
 
Polemonium californicum

As of April 2020 Kew's Plants of the World Online accepts 37 species.[1] Many are locally known simply as "Jacob's ladder".[4][5][6][7]

References

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  1. ^ a b "Polemonium caeruleum L." Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 8 April 2020.
  2. ^ Kew Plant List of Polemonium species, synonyms, unaccepted names
  3. ^ "Polemonium L." Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 8 April 2020.
  4. ^ Wilhelm, Gerould; Rericha, Laura (2017). Flora of the Chicago Region: A Floristic and Ecological Synthesis. Indiana Academy of Sciences.
  5. ^ Jepson Flora of California: Polemonium
  6. ^ Reznicek, A. A.; Voss, E. G.; Walters, B. S., eds. (February 2011). "Polemonium reptans". Michigan Flora Online. University of Michigan Herbarium. Retrieved 8 April 2020.
  7. ^ NRCS. "Polemonium". PLANTS Database. United States Department of Agriculture (USDA). Retrieved 8 April 2020.
  8. ^ NRCS. "Polemonium acutiflorum". PLANTS Database. United States Department of Agriculture (USDA). Retrieved 9 October 2015.
  9. ^ Maiz-Tome, L. 2016. Polemonium acutiflorum. The IUCN Red List of Threatened Species 2016: e.T64321387A67730462. https://dx.doi.org/10.2305/IUCN.UK.2016-1.RLTS.T64321387A67730462.en. Downloaded on 30 March 2020.