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Dichanthelium boreale (Nash) Freckmann - Northern Rosette Panic Grass

Order: Poales

Family: Poaceaedichanthelium boreale

Dichanthelium boreale (Nash) Freckmann

Synonymy: Panicum boreale Nash; Panicum calliphyllum Ashe

Lower Taxa: Panicum bicknellii Nash included in this description

Origin: Native

Habit: Rosette forming perennial grass

Habitat: Moist to wet soils

Range: Northern Valley and Ridge/Highland counties; poorly documented

Frequency: Rare

Rank/Status: S1/G5; Endangered

Wetland Status: FACW

Flowering & Reproduction: Vernal flowering phase May to early June, spikelets mature by late June-early July; autumnal panicles form late July-September; spikelets mature within month of pollination

Comments: Dichanthelium boreale, the Northern Panic Grass, is a rare wetland grass species confined to a few station in fewer counties.  The New Jersey Natural Heritage Program lists the species as S1 indicating fewer than 5 known populations.  The Chrysler Herbarium records Sussex, Morris and Somerset Counties as its New Jersey range. Similar habitat in Warren, Hunterdon and Mercer Counties may support this unusual northern rosette grass.  Mary Hough indicated sightings in 1983.

The FNA authors Freckmann and LeLong (Flora of North America, Volume 25) include Panicum bicknelli within the Dichanthelium boreale taxa.  The Flora of New Jersey Project does not concur with this combination.  FNJP’s authority, J. Arsenault, separates the two species based each species’ habitats,  state distributions and anatomical differences. 

Dichanthelium boreale (Nash) Freckmann occupies moist to wet woodlands, stream edges and bogs in the northern tier counties and on fertile clay loam soils of the Inner Coastal Plain and Cape May peninsula. Dichnathelium boreale cauline leaves are wide spread and divergent on upright culms.  The spikelets are solitary or with few on widely divergent branches, 2-2.2 mm. 

Panicum bicknelli Nash is a species that favors the southern Coastal Plain counties but has representative in suitable habitats. The plant has been described from the dry, more sterile sandy soils in Atlantic, Cape May, Cumberland, Gloucester and Warren counties.  Panicum bicknelli has distinct growth habit, forming narrow, crowded cauline leaves.  The spikelets are solitary on ascending branches, 2.3-2.8 mm.

Reference Specimens: Dichanthelium boreale (Nash) Freckmann: B. Fender, May 31, 1935, 1.5 mi. west Mullica HIll, Gloucester County, wooded slope, Chrylser Herbarium # 32452; Panicum bicknellii Nash: B. Long 50956, July 30, 1937;  ca. 1 mi. east of Manusuckin Cumberland County Chrylser Herbarium # 114481 

Author: J.R. Arsenault, 5/2012; revised 10/2012



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