John A. Roebling Memorial Park (part of the Trenton-Hamilton marsh complex)
Hamilton Township, Mercer County, New Jersey
257 acres

Gateway to the Hamilton/Trenton Marsh.

Directions:

From our meeting area in the parking lot south of Water Front Park we drove east on Lalor Street, right onto South Broad Street (where it says Welcome to Hamilton), and right onto Sewell Avenue; turned left at the dead end sign into the park and parked down by the water.

Spring Lake is the lake here.

History:

1708  -- Isaac Watson built and lived in the now the Historic Watson House, the oldest house in Mercer County.  The house is located in the park. The outside of the house remains the same, but the inside has changed.

1834  -- Delaware and Raritan Canal finished. (Remains of the canal located near Roebling Memorial Park below I-195 and the tracks of the Camden-Trenton Branch of Conrail.)  The D&R began where Crosswicks Creek enters the Delaware River.  Lock Number 1 was a tide lock.  A pier guided the boats in toward the lock.  Lock Number 4 was located just south of Lalor Street.

1919  -- death of  Dr. Charles C. Abbott (1843-1919), a doctor , archeologist and natural historian, who brought renown to the area.

1930s  --  Dorothy Cross studied the area.

1950s  --  the land for the park was given by the Roebling family.

today  --  The house is used as a State Headquarter for the Daughters of the American Revolution (D.A.R.).

Habitats:

fresh water marsh, an 18-acre lake (known locally as White City Lake)

Facilities:

fishing, bird watching, small picnic area (accessible from the Schiller Avenue entrance), boating (no gasoline motors)

PLANT LIST
Dr. Mary Leck

Trees:
Acer negundo (box elder maple)
Acer rubrum (red maple)
Ailanthus altissima (tree of heaven)
Albizia julibrissin (silk tree)
Betula nigra (river birch)
Elaeagnus umbellata (autumn olive)
Fraxinus americana (white ash)
Ilex opaca (American holly) planted
Liquidambar styraciflua (sweetgum) planted
Liriodendron tulipifera (tulip tree)
Morus alba (white mulberry)
Nyssa sylvatica (tupelo)
Paulownia tomentosa (empress tree)
Platanus occidentalis (sycamore)
Populus deltoides (cottonwood)
Prunus serotina (black cherry)
Quercus palustris (pin oak)
Rhus copallinum (winged sumac)
Rhus typhina (staghorn sumac)
Robinia pseudoacacia (black locust)
Salix babylonica (weeping willow)
Salix nigra (black willow)

Shrubs:
Alnus serrulata (smooth alder)
Buddleja davidii (butterfly bush) 9/18/99
Cornus amomum (swamp dogwood)
Ilex verticillata (winterberry holly)
Myrica pensylvanica (bayberry) planted
Rosa multiflora (multiflora rose)
Sambucus canadensis (common elderberry)
Viburnum dentatum var. lucidum (smooth arrowwood viburnum)

Vines:
Apios americana (groundnut)
Cuscuta sp. (dodder)
Lonicera japonica (Japanese honeysuckle)
Parthenocissus quinquefolia (Virginia creeper)
Smilax rotundifolia (round-leaved greenbrier)
Solanum dulcamara (bittersweet nightshade)
Toxicodendron radicans (poison ivy)
Vitis labrusca (fox grape)

Herbs:
Acalypha rhomboidea (three-seeded mercury)
Ambrosia artemisiifolia (common ragweed) 9/18/99
Apocynum cannabinum (Indian hemp dogbane)
Artemisia vulgaris (common mugwort) 9/18/99
Asclepias incarnata (swamp milkweed)
Asclepias syriaca (common milkweed)
Bidens frondosa (devil's beggar ticks) 9/18/99
Boehmeria cylindrica (false nettle)
Ceratophyllum demersum (coontail)
Chenopodium album (pigweed) 9/18/99
Chrysanthemum leucanthemum (ox-eye daisy) 9/18/99
Cirsium arvense (Canada thistle) 9/18/99
Commelina communis (Asiatic dayflower) 9/18/99
Daucus carota (Queen Anne's lace) 9/18/99
Desmodium sp. (tick trefoil)
Erechtites hieraciifolia (pilewort) 9/18/99
Eupatorium rugosum (white snakeroot) 9/18/99
Eupatorium serotinum (late flowering boneset) 9/18/99
Euphorbia nutans (eyebane spurge)
Glechoma hederacea (gill over the ground)
Heteranthera reniformis (mud plantain)
Helenium autumnale (common sneezeweed) 9/18/99
Heteranthera multiflora (mud plantain)
Heteranthera reniformis (mud plantain)
Hibiscus moscheutos (swamp rose mallow)
Impatiens capensis (orange jewelweed) 9/18/99
Lathyrus latifolius (everlasting pea) 9/18/99
Lemna sp. (duckweed)
Lespedeza capitata (round-headed bush clover)
Lespedeza cuneata (Chinese bush clover)
Linaria vulgaris (butter and eggs) 9/18/99
Lobelia siphilitica (great blue lobelia) 9/18/99
Lobelia cardinalis (cardinal flower) 9/18/99
Lycopus americanus (American water horehound) 9/18/99
Lythrum salicaria (purple loosestrife) 9/18/99
Nuphar sp. (spatterdock)
Oenothera biennis (common evening primrose) 9/18/99
Oxalis stricta (yellow wood sorrel) 9/18/99
Peltandra virginica (arrow arum)
Phytolacca americana (pokeweed)
Plantago lanceolata (English plantain) 9/18/99
Plantago major (common plantain)
Polygonum amphibium (water smartweed) 9/18/99
Polygonum arifolium (halberd-leaved tearthumb) 9/18/99
Polygonum cespitosum (cespitose smartweed) 9/18/99
Polygonum cuspidatum (Japanese smartweed) 9/18/99
Polygonum hydropiperoides (false water pepper) 9/18/99
Polygonum pensylvanicum (pink knotweed) 9/18/99
Polygonum punctatum (spotted smartweed) 9/18/99
Pontederia cordata (pickerelweed) 9/18/99
Potamogeton crispus (crisped pondweed)
Rudbeckia hirta var. pulcherrima (black-eyed Susan) 9/18/99
Sagittaria latifolia (broad-leaved arrowhead) 9/18/99
Smilacina racemosa (false Solomon's seal)
Solidago canadensis (Canada goldenrod) 9/18/99
Taraxacum officinale (dandelion) 9/18/99
Trifolium pratense (red clover) 9/18/99
Typha angustifolia (narrow-leaved cattail)
Utricularia sp. (bladderwort)
Verbascum thapsus (common mullein) 9/18/99
Verbena officinalis (white vervain)
Wolffia sp. (water meal)
Xanthium strumarium (clotbur)

Rushes and Sedges:
Cyperus bipartitus (cyperus)

Grasses:
Arthraxon hispidus (grass)
Digitaria ischaemum (smooth crab grass)
Echinochloa muricata (barnyard grass)
Eleusine indica (goose grass)
Microstegium vimineum (Japanese stilt grass)
Panicum clandestinum (deer-tongue panic grass)
Phragmites australis (giant reed grass)
Setaria faberi (nodding foxtail grass)
Setaria glauca (yellow foxtail grass)
Setaria viridis (green foxtail grass)
Tridens flavus (purple top grass)
Zizania aquatica (wild rice grass) 9/18/99

Ferns and Fern Allies:
Equisetum arvense (field horsetail)
Onoclea sensibilis (sensitive fern)
Thelypteris palustris (marsh fern)

At the marina:

Bidens bidentoides (southern estuarine beggar ticks) 9/18/99
Chenopodium ambrosioides (Mexican tea) 9/18/99
Helenium atumnale (sneezeweed) 9/18/99
Polygonum punctatum (dotted smartweed) 9/18/99
Vernonia noveboracensis (New York ironweed) 9/18/99

JOHN A. ROEBLING MEMORIAL PARK AND DUCK ISLAND OF THE HAMILTON-TRENTON MARSH, HAMILTON AND TRENTON, MERCER COUNTY, N.J., September 18, 1999.

This was the Saturday following the tremendous floods brought by Hurricane Floyd. This undoubtedly discouraged many field botanists from turning out. Fortunately, a class of ten students in a wetlands course from the University of Pennsylvania came out.

Blooming at the John A. Roebling Memorial Park were Ambrosia artemisiifolia (common ragweed), Artemisia vulgaris (common mugwort), Bidens frondosa (devil's beggar ticks), Chenopodium album (pigweed), Chrysanthemum leucanthemum (ox-eye daisy), Cirsium arvense (Canada thistle), Commelina communis (Asiatic dayflower), Daucus carota (Queen Annes lace), Erechtites hieraciifolia (pilewort), Eupatorium rugosum (white snakeroot) and E. serotinum (late flowering boneset), Helenium autmunale (common sneezeweed), Impatiens capensis (orange jewelweed), Lathyrus latifolius (everlasting pea), Linaria vulgaris (butter and eggs), Lycopus americanus (American water horehound), Lythrum salicaria (purple loosestrife), Oenothera biennis (common evening primrose), Oxalis stricta (yellow wood sorrel), Plantago lanceolata (English plantain), Polygonum amphibium (water smartweed), P. arifolium (halberd-leaved tearthumb), P. cespitosum (cespitose smartweed), P. cuspidatum (Japanese smartweed), P. hydropiperoides (false water pepper), P. pensylvanicum (pink knotweed), P. punctatum (spotted smartweed), Pontederia cordata (pickerelweed), Sagittaria latifolia (broad-leaved arrowhead), Taraxacum officinale (dandelion), Trifolium pratense (red clover), Verbascum thapsus (common mullein), and Zizania aquatica (wild rice grass).

Other interesting plants not in bloom were Arthraxon hispidus (grass), Asclepias incarnata (swamp milkweed), Ceratophyllum demersum (coontail), Hibiscus moscheutos (swamp rose mallow), Potamogeton crispus (crisped pondweed), Utricularia sp. (bladderwort), Wolffia sp. (water meal), and Xanthium strumarium (clotbur).

The group had lunch at the Trenton marina boat dock north of Duck Island. In bloom was the rare plant Bidens bidentoides (southern estuarine beggar ticks) along with Chenopodium ambrosioides (Mexican tea), Helenium atumnale (sneezeweed), and Vernonia noveboracensis (New York ironweed).

A sampling of the species blooming at Duck Island were Aster puniceus (purple-stemmed aster), Bidens laevis (showy bur marigold), Helianthus tuberosus (Jerusalem artichoke sunflower), Mikania scandens (climbing hempweed), Perilla frutescens (perilla mint), Polygonum arifolium (halberd-leaved tearthumb), P. punctatum (dotted smartweed), and P. sagittatum (arrow-leaved tearthumb), Pontederia cordata (pickerel weed), Solanum nigrum (black nightshade), and Vernonia noveboracensis (New York ironweed).

Other species were Amaranthus cannabinus (water hemp), Carex grayi (Gray's sack sedge), Eleocharis acicularis (spike rush), Elodea nuttallii (elodea), Heteranthera multiflora (mud plantain) and H. reniformis (mud plantain), Leersia oryzoides (rice cut grass), Ludwigia palustris (water purslane), Myriophyllum spicatum (water milfoil), Penthorum sedoides (ditch stonecrop), Potamogeton pectinatus (sago pond weed), Sagittaria subulata, Scirpus cyperinus (woolly grass bulrush), and Vaucheria sp. (an alga).

Total attendance was 15. The trip leaders were Drs. Mary and Charles Leck. Report prepared by Dr. Patrick L. Cooney.

On 17 February 2002 large mats of Wolfiella gladiata were found growing along the edge of beaver impounded areas along the trail at John A. Roebling Memorial Park (end of Sewell Ave., Hamilton, NJ). In the Wolfiella mats were plants of Lemna valdiviana.

Both Lemna valdiviana and Wolfiella gladiata are rare in NJ. There are
only four state records for Wolfiella (last 1962 Mannington Marsh collected by B. Hirst) and six for L. valdiviana (last 1975 Hunterton Co. collected by V. Abraitys). (Records were supplied by David Snyder).

Mary A. Leck and Charles F. Leck