Natural Communities of NH -- Photo Guide

Bayonet rush emergent marsh  (S2)



Bayonet rush emergent marshes
occur in shallow waters of ponds, lakes, and rivers with sandy bottoms or with thin organic layers over sand. They remain inundated for most or all of the growing season, although dry periods expose portions of the marsh. They are dominated by moderate to dense stands of bayonet rush (Juncus militaris) emerging from lake and river water, over 2 ft. deep at times. Bayonet rush is densest in water that is less than 1 ft. deep late in the season. Along shallow lake shores, these stands can extend out 30 m or more.

Characteristic Vegetation:
Bayonet rush is dominant. A common associate (sub-dominant in some examples) is three-square rush (Schoenoplectus pungens). Other common species include pickerel weed (Pontederia cordata), floating heart (Nymphoides cordata), water lobelia (Lobelia dortmanna), water shield (Brasenia schreberi), bladderworts (Utricularia spp.), milfoils (Myriophyllum spp.), bur-reeds (Sparganium spp.), and northern floating mannagrass (Glyceria borealis).

Species within the upper portion of stands where the water may draw down later in the summer include golden pert (Gratiola aurea), swamp candles (Lysimachia terrestris), mild water pepper (Persicaria hydropiperoides), stiff panic grass (Panicum rigidulum), marsh St. John's-wort (Triadenum virginicum), three-way sedge (Dulichium arundinaceum), mud rush (Juncus pelocarpus), spike-rushes (Eleocharis spp.), and pipewort (Eriocaulon aquaticum). The invasive purple loosestrife (Lythrum salicaria) also may be present. 


Good examples of this community occur at the Ossipee River (Freedom and Effingham) and Massabesic Lake (Auburn and Manchester). 

Bayonet rush emergent marshes often occur as part of emergent marsh - shrub swamp systems.


Bayonet rush emergent marsh along the Ossipee River (photo by Bill Nichols)
Bayonet rush emergent marsh along the Ossipee River in Effingham/Freedom (photo by Bill Nichols)

Bayonet rush emergent marsh at Massabesic Lake (photo by Bill Nichols)
Bayonet rush emergent marsh at Massabesic Lake in Auburn (photo by Bill Nichols)

Bayonet rush emergent marsh at Massabesic Lake in Manchester (photo by Bill Nichols)
Bayonet rush emergent marsh at Massabesic Lake in Manchester (photo by Bill Nichols)


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