River Road, Raritan Township, Hunterdon County, NJ
26 acres (part of the 1000-acre South Branch Reservation)

The Assicong Marsh is Hunterdon County’s largest fresh water marsh.


from the Clinton Area: Take Route 31 south approximately 10 miles. After crossing the South Branch of the Raritan River, make the first left-hand turn onto River Road. Proceed on River Road for 0.5 miles. The parking lot is on the left.

from the Flemington Area: Take Route 31 north from the Flemington Circle to the junction with Route 612 (Bartles Corner Road). At the traffic light, turn right and proceed 0.6 miles to River Road. Turn left and proceed 0.2 miles. The parking lot is on the right.


1974  --  the county acquires the Assicong Marsh as one of the first properties along the South Branch Reservation.

Hiking/Nature Trails:

none, Nature Study available.


7/26/04.  There is a short trail from the kiosk a little ways into the swampy area where there are lots of pin oak and silver maple.  (On the raised earth behind the swamp, a train ran through the preserve background.)  The trail goes just a little ways and then one has to bushwhack if more exploration is desired.  The area was very wet the day I was there.  From the swamp area I turned left and walked into the marshy/shrub swamp area.  There is a huge buttonbush near the water. 

From the shallow water area I turned left again and walked over to the main road.  Then I walked further along the road.  When I came to the end of the preserve line, I turned around and walked back to the parking area.  There is a nice piece of land with some good plants on the other side of River Road from the preserve. 

I walked along the road toward Route 523 checking out some more areas.  I was looking for a way into the woods, but no apparent trail or even an informal path made an appearance.  I also tried to start over and head to the swamp area and then go right instead of left.  But the right side looked too dense with vegetation and not at all inviting  Next stop for the day would be the Wings Section of the South Branch Reservation.  Dr. Patrick L. Cooney.

Dr. Patrick L. Cooney
* = plant found in bloom on date of field trip, 7/26/04

Acer negundo (ash leaf maple)
Acer rubrum (red maple)
Acer saccharinum (silver maple)
Acer saccharum (sugar maple)
Carya cordiformis (bitternut hickory)
Fagus grandifolia (American beech)
Fraxinus americana (white ash)
Juglans nigra (black walnut)
Juniperus virginiana (red cedar)
Morus alba (white mulberry)
Nyssa sylvatica (tupelo)
Ostrya virginiana (American hop hornbeam)
Prunus serotina (black cherry)
Quercus palustris (pin oak) -- lots
Quercus rubra (red oak)
Salix sp. (willow)
Sassafras albidum (sassafras)
Ulmus americana (American elm)

Cephalanthus occidentalis (buttonbush) *
Corylus sp. (hazel)
Cornus amomum (swamp dogwood)
Elaeagnus umbellata (autumn olive)
Lindera benzoin (spicebush)
Rosa multiflora (multiflora rose)
Rubus occidentalis (black raspberry)
Rubus phoenicolasius (wineberry)
Rubus sp. (black berry)
Viburnum prunifolium (blackhaw viburnum)

Calystegia sepium (hedge bindweed) *
Cuscuta sp. (dodder) on Polygonum sp.
Lonicera japonica (Japanese honeysuckle) *
Parthenocissus quinquefolia (Virginia creeper)
Sicyos angulatus (one-seeded cucumber vine)
Toxicodendron radicans (poison ivy)
Vitis spp. (fox grape)

Acalypha sp. (three-seeded mercury)
Alisma sp. (water plantain)
Alliaria petiolata (garlic mustard)
Allium vineale (field garlic) *
Ambrosia artemisiifolia (common  ragweed)
Ambrosia trifida (giant ragweed)
Amphicarpaea bracteata (hog peanut)
Arisaema triphyllum (jack in the pulpit)
Asclepias incarnata (swamp milkweed) *
Boehmeria cylindrica (false nettle)
Cicuta maculata (water hemlock) ?
Cichorium intybus (chicory) *
Cirsium arvense (Canada thistle) *
Cirsium vulgaris (bull thistle) *
Daucus carota (Queen Anne's lace) *
Dianthus armeria (Deptford pink) *
Dipsacus sylvestris (teasel) *
Erechtites hieraciifolia (pileweed)
Erigeron annuus (daisy fleabane ) *
Eupatorium rugosum (white snakeroot) *
Euphorbia maculata (spotted spurge)  *
Euthamia graminifolia (grass-leaved goldenrod) *
Galium trifidum (northern three-lobed bedstraw) *
Geum canadense (white avens) *
Glechoma hederacea (gill over the ground)
Hackelia virginiana (Virginia stickseed) *
Impatiens capensis (orange jewelweed) *
Lemna sp. (duckweed)
Linaria vulgaris (butter and eggs) *
Lobelia inflata (Indian tobacco) *
Ludwigia palustris (water purslane)
Lycopus sp. (bugleweed) *
Lycopus virginicus (Virginia bugleweed) *
Lysimachia nummularia (moneywort)
Lysimachia terrestris (swamp candles)
Medicago lupulina (black medick) *
Mimulus ringens (monkey flower) *
Oenothera biennis (common evening primrose) *
Oxalis sp. (yellow wood sorrel) *
Paronychia canadensis (forked chickweed)
Phytolacca americana (pokeweed) *
Pilea pumila (clearweed)
Plantago lanceolata (English plantain) *
Plantago major (common plantain)
Polygonum arifolium (halberd-leaved tearthumb)
Polygonum cespitosum (cespitose knotweed) *
Polygonum cuspidatum (Japanese knotweed) *
Polygonum sagittatum (arrow-leaved tearthumb)
Polygonum sp. (a pink polygonum) *
Polygonum sp. (a hot white polygonum) *
Polygonum virginianum (jumpseed knotweed) *
Prunella vulgaris (self-heal) *
Rumex crispus (curled dock)
Scutellaria lateriflora (mad-dog skullcap) *
Solanum dulcamara (bittersweet nightshade) *
Solidago spp. (goldenrod)
Sonchus sp. (sow thistle) *
Sparganium sp. (burreed) lots of it
Symplocarpus foetidus (skunk cabbage)
Taraxacum officinale (common dandelion) *
Typha latifolia (broad-leaved cattail)
Verbascum blattaria (moth mullein) *
Verbascum thapsus (common mullein)
Verbena hastata (blue vervain) *
Verbena urticifolia (white vervain) *
Vernonia noveboracensis (New York ironweed) *
Veronica officinalis (common speedwell)

Juncus tenuis (path rush)

Carex crinita (fringed sedge)
Carex stricta (tussock sedge)
Carex typhina (sedge)
Cyperus sp. (nut or umbrella sedge)
Eleocharis ovata (spikerush)
Scirpus cyperinus (woolly grass bulrush)

Dactylis glomerata (orchard grass)
Digitaria sp. (crab grass)
Echinochloa sp. (barnyard grass)
Elymus hystrix (bottle brush grass)
Microstegium vimineum (Japanese stilt grass) 
Phalaris arundinacea (reed canary grass)
Phleum pratense (Timothy grass)
Setaria faberi (nodding foxtail grass)
Setaria glauca (yellow foxtail grass)
Setaria viridis (green foxtail grass)

Ferns and Fern Allies:
Equisetum arvense (field horsetail)
Onoclea sensibilis (sensitive fern)
Polystichum acrostichoides (Christmas fern)