State Status: N
PBS Status: Pennsylvania Threatened (PT)
Global Rank: G4
State Rank: S1S2
Godfrey's throughhwort (Eupatorium godfreyanum) is a perennial herb with hairy stems that may grow from 60cm to 1.5m high. The leaves are oppositely arranged, generally lance-shaped, 7-11cm long, toothed on the margin, pointed at the tip, and attach directly to the stem without a stalk. The flowers, appearing from August to October, are grouped into small flower heads and are arranged in branched, open clusters at the top of stems.
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 PA Biological Survey (PABS) considers Godfrey's throughwort to be a species of special concern, based on the few occurrences that have been recently confirmed. It does not have a PA legal rarity status, but has been assigned a suggested rarity status of Threatened by PABS. Only a few occurrences have been documented in the state.
It grows on dry slopes, woodland borders, and clearings.
Flowers late June through October
In Pennsylvania, it has been documented historically in a few eastern counties, particularly those bordering the
Populations of Godfrey's throughwort have threats from natural succession, invasive species, and the indiscriminate application of herbicide.
Given the preference of the species for open habitats, active management - fire, mowing, or invasive species removal - may be required in order to create the proper successional stage and ecological requirements for the species to thrive.
Conservation Status Map
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.