Species Factsheets

Eleocharis parvula

Dwarf Spike-rush

View as PDF

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

Global Rank: G5 rank interpretation
State Rank: S1

Did You Know?

This spcies is one of the most resilient and easy to keep "carpet" plants, so it's good for outdoor area or even fishtanks.

Eleocharis parvula


Dwarf spike-rush (Eleocharis parvula) is a diminutive perennial herb typically some centimeters in height. The leaves are reduced to scales that are located at the base of the stem, which is the main photosynthetic portion of the plant. The flowers, appearing from June to September, are microscopic in size and are grouped together inside a scaly cluster at the top of the stem. The individual fruits are only about one millimeter in length and are three-sided.

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 PA Biological Survey (PABS) has assigned dwarf spike-rush a rarity status of Endangered, based on the limited number of populations that have been confirmed, the small population sizes, the limited state range, and the specialized habitat.


Dwarf spike-rush grows in intertidal marshes, mudflats, and on shorelines. The intertidal populations are subjected to daily cycles of exposure and inundation.

Survey Dates

Flowers, fruits July - October


In Pennsylvania, it has been documented historically in a few southeastern counties and in Erie County.



The known populations have threats from exotic species, dredging and filling, and water pollution.

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.
PNHP is a partnership between The Department of Conservation and Natural Resources,
the Pennsylvania Game Commission, the Pennsylvania Fish and Boat Commission,
and the Western Pennsylvania Conservancy.
DCNR Home Page
PA Game Commission Home Page
PA Fish and Boat Commission Home Page
Western PA Conservancy Home Page
DCNR Home Page PNHP | Forestry Home | Contact Us | Search This Site
© 2019 PA Department of Conservation and Natural Resources
DCNR Home Page