Species Factsheets

Polemonium vanbruntiae

Jacob's Ladder

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State Status: Pennsylvania Endangered (PE)
PBS Status: Pennsylvania Endangered (PE)
Federal Status:

Global Rank: G3G4 rank interpretation
State Rank: S1

Did You Know?

Neighboring state New York has the greatest number of populaitons in the country and some of the largests populations of this species in the world.

Polemonium vanbruntiae


Jacob's ladder (Polemonium vanbruntiae) is a perennial herb up to 1m in height. The leaves are alternately arranged and divided into numerous leaflets with entire margins. The individual flowers, appearing in late June and early July, have blue petals and protruding stamens and style. The fruit is a many-seeded capsule. A more common and widespread species, Polemonium reptans, is similar but is smaller in size, has the stamens and style not protruding from the flower, has more of a woodland habitat, and blooms in spring.

Rank Justification

Critically imperiled in the nation or state because of extreme rarity (often 5 or fewer occurrences) or because of some factor(s) such as very steep declines making it especially vulnerable to extirpation from the state.


The Jacob's ladder has been given a status of Endangered on the Plants of Special Concern in Pennsylvania list by the Pennsylvania Biological Survey and the Department of Conservation and Natural Resources, based on the relatively few populations that have been documented in the state. It is considered a globally rare species by the Natural Heritage Program.


The species grows in wet soil in woods, thickets and openings.

Survey Dates

Flowers June - early July


It is known historically from several widely scattered occurrences in Pennsylvania, although all of the currently known populations are in the northeastern part of the state.


Conservation Status Map


Map Legend

NatureServe. 2017. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available https://explorer.natureserve.org.


  • NatureServe. 2018. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available at https://www.natureserve.org/explorer
  • Pennsylvania Natural Heritage Program. 2018.
  • Rhoads, A.F. and W.M. Klein, Jr. 1993. The Vascular Flora of Pennsylvania. American Philosophical Society, Philadelphia, Pennsylvania. Rhoads, A.F. and T.A. Block.
  • 2007. The Plants of Pennsylvania: An Illustrated Manual. 2nd edition. University of Pennsylvania Press, Philadelphia, Pennsylvania.
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