New Jersey Field Office
Northeast Region

Hirst Brothers’ Panic Grass (Dichanthelium [Panicum] hirstii) [candidate]

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Additional Information


Intermittent ponds

Main Threats:
Habitat loss
Hydrologic change
Canada geese

Fun Fact:
Hirsts' panic grass is named for two brothers- amateur botanists- who discovered the species in New Jersey.


Hirst Brothers’ panic grass distribution in New Jersey by municipality
Map of Hirsts' panic grass distribution in New Jersey by municipality

Hirst Brothers’ panic grass was added to the list of Federal candidate species in 1998. The species is State-listed as endangered.

A perennial member of the grass family, Hirst Brothers’ panic grass produces upright (erect) leafy flowering stems (culms) from May to October. The clustered culms grow 8 to 23 inches high. The flower cluster (panicle) is 1 to 4 inches long and sparsely flowered with finely hairy spikelets. Panicles sometimes stay hidden among the densely branched stems. The narrow leaf blades are 1 to 5 inches long and variably smooth or hairy. Spring culms are produced in May and June, while autumnal culms grow from August through the first frost.

Named for two brothers who discovered the species in New Jersey, Hirst Brothers’ panic grass occurs in Coastal Plain intermittent ponds, usually in wet savanna or pine barren habitats. The species requires habitats that are at least intermittently wet, receiving full sun to light shade, and substrates that are organic but firm. Hirst Brothers’ panic grass occurs in flat-bottomed depressions with substantial water-level fluctuations dependent on rainfall. The species relies on periods of standing water to keep competing species at a minimum. Habitats supporting Hirst Brothers’ panic grass may have historically burned during dry cycles, which may also help maintain early successional conditions by preventing encroachment of trees. Individual populations can vary dramatically in size from year to year. In some years, plants may not appear.

Threats to Hirst Brothers’ panic grass include habitat loss, natural competition and succession, hydrologic alterations, and grazing by resident Canada geese (Branta canadensis).

Candidate species are species that the U.S. Fish and Wildlife Service (Service) has determined warrant listing under the Endangered Species Act and await formal listing. Although these species receive no substantive or procedural protection under the Endangered Species Act until formal listing, the Service encourages consideration of candidate species in project planning.


Species Range: Hirst Brothers’ panic grass occurs in New Jersey, Delaware, and North Carolina. The species historically occurred in Georgia.

Distribution in New Jersey: Hirst Brothers’ panic grass is currently known to occur in Burlington and Atlantic Counties.

Last updated: January 28, 2014
New Jersey Field Office
Northeast Region Ecological Services
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