Coastal endangered plants inventory a report on the Seabrook Dunes, its vegetation and flora

[From the U.S. Government Printing Office, www.gpo.gov]

COASTAL ENDANGERED PLANT INVENTORY

A report on the Seabrook Dunes,

its vegetation and flora

Debra A. Dunlop, Garrett E. Crow, and Timothy J. Bertrand

15 February 1983

Department of Botany and Plant Pathology
QK and
86 N. H. Agricultural Experiment Station
.U6 University of New Hampshire
D8 Durham, NH 03824
1983

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COASTAL ENDANGERED PLANTS INVENTORY

A report on the Seabrook Dunes,

its vegetation and flora

Debra A. Dunlop, Garrett E. Crow and Timothy J. Bertrand

preparation of this report was financed
in part,by the Coastal Zone Manager@ent Act
of 1972, as amended, administered by the
office of Ocean and Coastal Pesource Man-
agexcent, National Oceanic and Atnospheric
Mministration, through a grant provided by
the New Hampshire Office of State Plaming.

15 February 1983

Department of Botany and Plant Pathology
and
N. H. Agricultural Experiment Station
University of New Hampshire
Durham, NH 03824

Page 1

INTRODUCTION

In the summer of 1982 a project was established, funded

by the Department of Commerce, NOAA, Office of Ocean and

Coastal Resource Management through the New Hampshire Office

of State Planning, aimed at contributing to the development

of baseline data on coastal resources, particularly plants

regarded. as rare, threatened, or endangered in New

Hampshire. As part of this overall project, particular

attention was directed at the Seabrook Dunes. This report

provides a description and inventory of the natural dune

vegetation with special recognition given to those species

considered rare for the state.

The coastline of New Hampshire represents a

transitional zone between the typical, sandy beaches and

barrier beach islands with extensive salt marsh development,

characteristic of the coast of the South to Middle Atlantic

states, and the rocky coastline characteristic of Maine

(C-row and Storks, 1980). Extensive dune and salt marsh

habitat once extended from Seabrook to Hampton Beach, and

intermittently northward.

A typical coastal dune system consists of a foredune,

an interdune, and a backdune. The foredune ridge receives
the greatest impact of coasta@ storms and few species are

able to colonize it. Behind the foredune a more stable, yet

dynamic, interdune of low, undulating sands supports a more

Page 2

diversified flora. A backdune formation of higher dunes and

deep hollows develops furthest from the beach and is

characterized by shrub thickets and sunken forests. The

dune ecosystem at nearby Plum Island, Massachusetts

represents the best preserved dune system north of Cape Cod

(cf. McDonnell, 1979a).

The sand dune ecosystem is important to us ecologically

and economically for two reasons: 1) it provides a natural

buffer protecting the coast from the impact of severe storms

(particularly northeasters) and tropical hurricanes, and 2)

it provides recreational opportunities (McDonnell, 1979).

In New Hampshire the latter reason has been readily

recognized, as the all-too-short coastal zone has

experienced intense pressures from development and the

pressure on this valuable resource is not likely to ease.

Nearly all of the dune habitat has been exploited for resort

related purposes. At the Seabrook dunes the once extensive

interdune is now replaced by houses and summer cottages and

all that remains is a remnant a once healthy sand dune

ecosystem. It is this backdune community which is the focal

point of this study.

4W Page 3

PHYSICAL FEATURES

The Seabrook backdune community, which occupies a site

of approximately 56 acres in the southeastern corner of the

Town of Seabrook, constitutes the only remnant of sand dune

formation in New Hampshire. Designated as "The Sands" on

the USGS Hampton Quadrangle topographical map, the Seabrook

dunes lie east of the extensive Seabrook salt marsh and the

Blackwater River (figs. 2, 3). To the south the dunes are

bordered by a small portion of salt marsh which separates

the area from adjacent commercial properties. The northern

boundary, formed by salt marsh and Cross Beach Road

(unimproved), is periodically flooded by high tides. This

road leads out onto the marsh to a few residential buildings

designated on the topographical map as "Riverside." Just

north of Cross Beach Road are additional commercial

establishments. To the east, the dunes abut Route 1A for

approximately 5440 feet. Along this road, a number of

commercial enterprises and residential homes have already

;0 obliterated the interdune community and are encroaching on
the backdune community (figs. 2, 3).

METHODS

The project, undertaken to provide an inventory of the

natural dune vegetation, was divided into two parts: 1) a

description of the composition, structure, and distribution

Page 4

of the vegetation and 2) a floristic documentation of the

dune's flora with special recognition given to those species

that are considered rare for New Hampshire.

Aerial photos were used to delineate all vegetated

areas. These areas were evaluated in the field for

physiognomy and species composition. Dominant species were

used to describe each vegetation type. Quantitative data

analysis using quadrats was not employed.

The floristic study was conducted through a systematic

reconnaissance of the area once each week beginning in May

1982 and continuing through October 1982. Collections of

all vascular plant species were made and data on relative

abundance and habitat were recorded in the field. Voucher

specimens were deposited in the Hodgdon Herbarium (NHA) at

the University of New Hampshire. The result of this part is

a detailed list of the flora.

It should be noted here that the residential properties

along Route 1A were circumscribed within the area on the

vegetation map because of their direct impact on the dune

community. The floristic study was not extended to the

private property nor to the roadside immediately adjacent to

Route 1A. These disturbed, weedy areas are quite different

and no longer reflect the natural dune vegetation.

Page 5

VEGETATION

Six vegetation types were recognized for the Seabrook

backdune community and adjacent salt marsh. These are

defined on physiognomy and dominant plant species. The six

types are:

1) Sunken Forest
2) Dunegrass
3) Thickets
a) Tall Thicket
b) Short Shrub Thicket
4) Wet Swale
5) Salt Marsh
6) Drift-line

The most conspicuous vegetation type is the sunken

forest. These heavily wooded areas form in the deeper

protected hollows between the highest dunes and it is here

that many trees reach their maximum height in the dune

community. Surrounding these high dunes and sunken forests

are low dunes, with a characteristic grassland appearance

where the dunegrass vegetation type is predominant.

Scattered among these low dunes is a mixture of shrubby and

arborescent thickets. Some thickets are dominated by low

shrubs less than 2 meters in height and hence are called

short shrub thickets, whereas others are dominated by small

trees, over 2 meters in height, and therefore are called

tall thickets. In the isolated hollows of the low dunes,

wet swales provide a habitat for a number of wetland

species. Although the wet swales are few in number, they

possess a unique assemblage of plants. The fifth vegetation

type, salt marsh, is contiguous with the dune sands on all

Page 6

sides but the east. This high salt marsh is frequently

inundated by high tides throughout the year and the plants

are well adapted to this saline environment. To the west

the boundary between salt marsh and dunes is somewhat

transitional. In these areas, the dunes are very low and

periodically experience inundation by very high storm tides

which leave behind large amounts of salt marsh debris.

These areas form a sixth vegetation type, the drift-line.

Following is a description of the six vegetation types,

emphasizing the dominant species (cf. vegetation map and

aerial photographs, figs. 1, 2, 3).

The vegetation map was constructed from aerial

photographs and from on-site evaluations of the individual

vegetation types. Although the map suggests abrupt

boundaries between the vegetation types, there are

transitional zones composed of species from each type.

Sunken Forest

In the backdune, four areas have been designated as

Sunken forests. All of these areas are heavily wooded and

dominated by a tall canopy of Prunus serotina (black

cherry), Amelanchier stolonifera (shadbush), Populus

tremuloides (trembling aspen), Acer rubrum (red maple) and

occasionally by Pinus rigida (pitch pine). The understory

is dominated by Lonicera morrowi (honeysuckle), Berberis

vulgaris (barberry), Toxicodendron radicans (poison ivy),

and Parthenocissus quinquefolia (Virginia creeper). In

Vegetation of Seabrook Dunes

4
Salt Marsh

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IN

US ROUtO IA

SCALE- 1 inch equals approx. 454 feet

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Fig. 2. Aerial photograph of Seabrook Dunes. 1982.
Photo courtesy of USDA-ASCS, Rockingham Co., NH

Fig. 3. Oblique aerial view of Seabrook Dunes. 1978.
Photo by Garrett E. Crow

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Page 7

addition, many herbaceous species are common: Aralia

nudicaulis (wild sarsaparilla), Maianthemum canadense (false

lily-of-the-valley), Arenaria lateriflora (grove sandwort),

and Smilicina stellata (false Solomon's seal). In the open

areas along the fringes of the sunken forests, Myrica

pensylvanica (bayberry) and Prunus maritima (beach plum) are

very abundant.

Dunegrass

The vegetation of the low dunes is dominated by grasses

and other low herbaceous plants. Ammophila breviligulata

(beach grass) is the most abundant species and particularly

important in dune stabilization. It spreads rapidly by

underground stems and colonizes open sands. Andropogon

scoparius (little blue stem) and Danthonia spicata

(poverty-grass) are common grasses in the southern portion

of the backdune community. Common plants are L4thyrus

japonicus (beach pea), Lechea maritima (pinweed),

Polygonella articulata (joint weed), and Cyperus filiculmis

(sedge). Solidago sempervirens (seaside goldenrod) is very

abundant throughout this vegetation type. In addition,

,large mats of Hudsonia tomentosa (beach heather) carpet

areas of the low dunes.

Page 8

Thickets

The most difficult vegetation type to characterize is

the mixture of shrubby and arborescent thickets that occur

throughout the low dunes. This catagory has been subdivided

into two types: tall and short shrub thickets.

The tall thickets, the less common of the the two, form

in the more stable areas of the low dunes and share species

in common with the sunken forests. They differ in that the

trees are smaller and the shrub layer very dense. The

canopy in the tall thickets varies but it is most often

composed of Populus tremuloides (trembling aspen), Prunus

serotina (black cherry), Amelanchier stolonifera (shadbush),

and occasionally Acer rubrum (red maple) and Pinus rigida

(pitch pine). Other species common to the tall thickets are

Amelanchier canadensis (shadbush), Rosa virginiana (rose),

Parthenocissus quinquefolia (Virginia creeper), Berberis

vulgaris (barberry), Viburnum recognitum (arrow-wood) and

the ubiquitous Toxicodendron radicans (poison ivy).

The second thicket type, the short shrub thicket, is

widespread on protected slopes and hollows of the low dunes.

Two species, Myrica pensylvanica (bayberry) and Prunus

maritima (beach plum), form extensive stands. Other common

species associated with the short shrub thickets are Rosa

virginiana (rose), Achillea millefo-lium (yarrow), Oenothera

parviflora (evening-primrose), Polygonum scandens (false

buckwheat) and Toxicodendron radicans (poison ivy).

Page 9

Wet Swale

Two types of wet swales occur in the hollows of the low

dunes. One is largely a cranberry swale with Vaccinium

macrocarpon (large cranberry) forming large dense mats where

the other, the Juncus swale, is dominated by thick stands of

Juncus balticus (rush). Bordering each swale, Aronia

prunifolia (purple chokeberry), Ilex verticillata

(winterberry), Triadenum virginicum (marsh St. John's-wort),

and Toxicodendron radicans (poison ivy) are very common.

Salt Marsh

The high marsh bordering the backdune is dominated by

the salt marsh grasses Spartina patens and Spartina

alterniflora. Among these grasses Limonium carolinianum

(sea lavender), Plantago maritima (sea plantain), and

Triglochin rnaritima (arrow-grass) are very common. Along

the upper edge of the marsh, Juncus gerardi (black-grass)

and Distichlis spicata (spike grass) form dense stands with

Salicornia europaea (glasswort), Suaeda linearis

(sea-blite), S. maritima (sea-blite), and S. richii

(sea-blite).

Drift-line

Many low areas along the border of the salt marsh and

backdune community are occasionally inundated by very high

storm tides. As the tides subside they leave behind large

amounts of salt marsh detritus and debris such as boat

Page 10

fragments, tires, cans, bottles, and an occasional shoe.

This debris separates the dune grasses from the more salt

tolerant species. Few plants can grow through these dense

piles of debris, but along the lower edge Spergularia marina

(sand-spurry) borders thick stands of Spartina patens (salt

marsh grass). Limonium carolinianum (sea lavender) and

Puccinellia maritima (alkali-grass) are also common. The

drift-line area is conspicuously lower in species diversity

as compared with the numerous salt tolerant species

occupying the high salt marsh.

Page 11

FLORA OF SEABROOK DUNES

The following list of vascular plants documents the

flora of the Seabrook dunes study area. The list is

arranged alphabetically by family under the general

catagories of ferns, gymnosperms, and angiosperms (flowering

plants--monocots and dicots). Within each family, genera

and species are also listed alphabetically to facilitate the

use of this flora. Identifications were primarily based on

Gray's Manual of Botany (Fernald, 1950) and A Manual of

Vascular Plants of Northeastern United States and Adjacent

Canada (Gleason and Cronquist, 1963). Voucher specimens

cited as "CZ" were collected by one or more of the authors.

Particular attention was given to those species of the

backdune community that are considered rare for the state.

These species are asterisked on the floristic list and

special notes on their abundance, distribution and habitat

follow the floristic list.

Page 12

FERNS AND FERN ALLIES

OSMUNDACEAE (Royal Fern Family)

Osmunda cinnamomea L. (cinnamon fern). Occasional; in
sunken forest and wet swale. CZ 304, 502.

Osmunda regalis L. (royal fern). Occasional; in sunken
forest. CZ 300.

POLYPODIACEAE (Fern Family)

Onoclea sensibilis L. (sensitive fern). occasional; in
moist areas of shrub thicket behind ridge of dune.
McDonnell 928.

Thelypteris palustris Schott. (marsh fern). Uncommon; in
wet swale. CZ 654.

GYMNOSPERMS

CUPRESSACEAE (Cypress Family)

Juniperus communis L. (common juniper). Uncommon; in
thickets. CZ 80, .657.

PINACEAE (Pine Family)

Pinus rigida L. (pitch pine). Uncommon; a few trees in
sunken forests and thickets. CZ 13, 68, 606; Crow 2515.

Page 13

ANGIOSPERMS

DICOTS

ACERACEAE (Maple Family)

Acer rubrum L. (red maple). Common; in sunken forest.
@ffZ 15, 31, 656.

ANACARDIACEAE (Cashew Family)

Rhus copallina L. (dwarf sumac, shining sumac). Uncommon;
a few plants on fringes of sunken forest. CZ 233, 405.

Rhus typhina L. (staghorn sumac). occasional; in
tF-1-ckets and on fringes of sunken forests. CZ 205, 495.

Toxicodendron radicans (L.) Kuntze (poison ivy).
Abundant; throughout backdunes. CZ 152.

AQUIFOLIACEAE (Holly Family)

Ilex verticillata (L.) Gray (winterberry). Occasional;
in wet swales and thickets and uncommon in sunken forest.
CZ 207, 212, 400, 503, 504, 515, 588, 659.

ARALIACEAE (Ginseng Family)

Aralia nudicaulis L. (wild sarsaparilla). Common; in
sunken forests. CZ 8, 50, 103, 513.

ASCLEPIADACEAE (Milkweed Family)

Asclepias syriaca L. (common milkweed). Frequent; in low
dune area and occasional in sunken forest. CZ 180, 226.

ASTERACEAE/COMPOSITE (Sunflower Family)

Achillea millefolium L. (yarrow). Frequent; on edge of
sunken forest, in low dune areas, and in thickets. CZ 86,
111, 125, 230, 493, 640. (including Achillea lanulosa
Nutt.)

Ambrosia, artemisiifolia L. (common ragweed). Uncommon;
in disturbed area in low dune areas. CZ 438.

*Artemisia caudata Michx. (wormwood). occasional in low
dune areas with a few plants at the northern edge of Sunken
Forest No. 2 and northern thicket; edge of abandonded
building. CZ 318, 371, 481, 580; McDonnell 920.

Page 14

Aster linariifolius L. (aster). occasional; in low dune
areas. CZ 652.

Chrysanthemum leucanthemum L. (ox-eye daisy). Occasional;
in disturbed area on edges of sunken forest. CZ 95.

Erigeron canadensis L. (horseweed). occasional; in
roadside areas. CZ 404.

Erechtites hieracifolia (L.) Raf. (fireweed). Occasional;
in low dune areas and thickets. CZ 623, 648.

Gnaphalium. obtusifolium L. (catfoot). Occasional; in low
dune area. CZ 486, 564; Crow 2489.

Hieracium florentinum All. (king devil). Occasional; in
low dune areas. CZ 78.

Hieracium pilosella L. (mouse-ear). Uncommon; in
disturbed area on edge of sunken forest. CZ 90.

Lactuca biennis (Moench) Fern. (wild lettuce). Frequent;
in wet swale and on the edges of thickets and sunken
forests. CZ 403, 433, 508, 627.

Solidago rugosa Ait. (goldenrod). Occasional; in sunken
forests and thickets. CZ 397, 571, 619, 642.

Solidago sempervirens L. (seaside goldenrod). Common; in
low dune area and edges of thickets and sunken forests. CZ
506, 570, 587, 635.

BERBERIDACEAE (Barberry Family)

Berberis vulgaris L. (common barberry). Common; in
sunken forests. CZ 10, 36, 46, 94, 102, .206, 396, 497, 582.

BETULACEAE (Birch Family)

Betula populifolia Marsh. (gray birch). Single tree in
wet swale. CZ 77.

BRASSICACEAE/CRUCIFERAE (Mustard Family)

Barbarea vulgaris R. Br. (common winter-cress).
Occasional; along roadside. CZ 92.

Cakile edentula (Bigel.) Hook. (sea-rocket). Common; in
low dune areas and edges of thickets. CZ 196, 571.

Sisymbrium altissimum L. (tumble-mustard). Common; edge
of sunken forest. CZ 108.

Page 15

CAPRIFOLIACEAE (Honeysuckle Family)

Lonicera X bella Zabel (hybrid honeysuckle). Common; in
sunken forest. CZ 6.

Lonicera morrowi Gray (honeysuckle). Common; in sunken
forest and thickets. CZ 9, 99, 240, 258, 644.

Sambucus canadensis L. (common elderberry). occasional;
in sunken forests. CZ 182, 201, 234.

Viburnum recognitum Fern. (arrow-wood). Common; in
thickets, sunken forests, and wet swales. CZ 127, 237, 436,
608, 639.

CARYOPHYLLACEAE (Pink Family)

Arenaria lateriflora L. (grove sandwort). Common; in
sunken forests and wet swale. CZ 3, 48, 51.

*Arenaria peploides L. (seabeach sandwort). One plant on
west side of Rt. 1A about 15 meters from turnoff to
Riverside, about 4 meters from edge of road in strand line.
CZ 665.

Lychnis alba L. (white cockle). Occasional; along
roadside. CZ 93.

Spergularia marina (L.) Griseb. (sand-spurrey). Common;
in salt marsh. CZ 217, 374, 598.

CELASTRACEAE (Staff-tree Family)

Celastrus orbiculatus Thunb. (bittersweet). occasional;
in sunken forest. CZ 105.

Celastrus scandens L. (climbing bittersweet). Uncommon;
in thicket. CZ 594.

CHENOPODIACEAE (Goosefoot Family)

Atriplex glabriuscula Edmondston (orach). Occasional in
wet pan near salt marsh. Crow 2512.

Atriplex patula L. var. 'littoralis (orach). Common; in
salt marsh. CZ 599, 607.

Chenopodium album L. (pigweed). Common; in low dune
areas. CZ 368, 369, 482, 509, 605; Crow 2506. (including
Chenopodium f-ance'olatum Muhl.)

*Salicornia bigelovii Torr. (dwarf saltwort, dwarf
glasswort). Occasional; at north end of Seabrook backdunes
in area inundated by very high tides. Few plants in open
mud/sand patches. CZ 667; Hodgdon and Steele 40452.

Page 16

Salicornia europaea L. (glasswort, chickenclaws). Common;
in salt marsh. CZ 491, 597.

*Salicornia virginica L. (woody glasswort, leadgrass).
Tocally abundant; in high marsh north of dunes and Cross
Beach Road, adjacent to Rt. 1A. CZ 575, 666; Hodgdon and
Steele 10584, 15104.

Suaeda linearis (Ell.) Moq. (sea-blite). Occasional; in
salt marsh. CZ 489.

Suaeda maritima (L.) Dumort. (sea-blite). Occasional; in
salt marsh. CZ 604; Crow 2491.

Sueada richii Fern. (sea-blite). occasional; in salt
marsh. CZ 603, 664.

CISTACEAE (Rockrose Family)

*Hudsonia tomentosa Nutt. var. tomentosa (beach heather,
false heather, beach heath). Common; in low dune areas.
CZ 55, 67, 88,, 478, 581, 593; Szepan 1090-413; Crow .2499.

Lechea maritima Leggett (pinweed). Common; in low dune
areas. CZ 322, 376, 389, 484, 569, 663; Crow 2498.

CLETHRACEAE (White Alder Family)

Clethra alnifolia L. (sweet pepperbush). Uncommon; in
sunken forest. CZ 100.

CLUSIACEAE/GUTTIFERAE (St. John's-wort Family)

Hypericum gentianoides (L.) BSP. (orange-grass).
occasional; along roadside. CZ 388.

Hypericum perforatum L. (common St. John's-wort).
Occasional; on edges of sunken forests and in thickets. CZ
184, 185, 198r 204, 297.

Triadenum virginicum (L.) Raf. (marsh St. John's-wort).
occasional; in wet swale. CZ 380, 658.

ERICACEAE (Heath Family)

Gaylussacia baccata (Wang.) K. Koch (huckleberry).
--'Sehind ridge of dune. McDonnell 952.
Common; in thicket

Lyonia ligustrina (L.) DC. (maleberry or male-blueberry).
Common; in shrub thicket behind ridge of dune.
McDonnell 949.

Vaccinium corymbosum L. (highbush blueberry). Uncommon;
in sunken forest. CZ 26, 29.

Page 17

Vaccinium macrocarpon Ait. (large cranberry). Locally
abundant; in wet swales. CZ 183, 211, 381, 576.

EUPHORBIACEAE (Spurge Family)

Euphorbia esula L. (leafy spurge). Occasional; in sunken
forests and low dune areas. CZ 7, 45, 87, 209.

Euphorbia polygonifolia L. (seaside spurge). occasional;
fow dune areas. CZ 321, 662.

FABACEAE/LEGUMINOSAE (Bean Family)

Lathyrus japonicus Willd. (beach pea). occasional; in
low dune areas. CZ 58, 91, 199.

Trifolium arvense L. (rabbit-foot clover). Common; edge
of sunken forest. CZ 434.

Trifolium repens L. (white clover). Common; edge of
sunken forest. CZ 107.

FAGACEAE (Beech Family)

Quercus velutina Lam. (black oak). occasional; in
sunken forest. CZ 203.

LYTHRACEAE (Loosestrife Family)

Lythrum salicaria L. (purple loosestrife). Occasional;
edge of sunken forest. CZ 302.

LAMIACEAE/LABIATAE (Mint Family)

Teucrium canadense L. (American germander). Common; on
edge of sunken forest. CZ 298, 439, 520, 647. (including
var. angustatum Gray and var. occidentale (Gray) McClintock
and Epling)

MYRICACEAE (Bayberry Family)

Comptonia peregrina (L.) Coult. (sweet fern). Occasional;
edge of sunken forest. CZ 27.

Myrica pensylvanica Loisel. (bayberry). Abundant; in
thickets and edges of sunken forests. CZ 17, 20, 32, 69,
97, 200, 492, 613, 637; Crow 2495, 2497.

ONAGRACEAE (Evening-primrose Family)

Epilobium glandulosum Lehm. (willow herb). occasional;
in wet swale. CZ 578.

Oenothera parviflora L. (evening-primrose). Common; in
low dune areas and on edge of sunken forest. CZ 195, 398,

Page 18

435, 480.

PAPAVERACEAE (Poppy Family)

Chelidonium majus L. (celadine). Occasional; on edge of
sunken forest. CZ 153.

PLANTAGINACEAE (Plantain Family)

Plantago maritima L. ssp. juncoides (Lam.) Hulten.
(seaside-plg-ntain). Common; in salt marsh. CZ 378.

PLUMBAGINACEAE (Leadwort Family)

Limonium carolinianum (Walt.) Britt. (sea lavender),.
Common; in salt marsh. CZ 216, 270; Crow 2490.
(including Limonium nashii)

POLYGONACEAE (Buckwheat Family)

Rumex acetosella L. (sheep-sorrel). Frequent; on edge of
sunken forests and in low dune areas. CZ 49, 71, 84, 194.

Polygonella articulata (L.) Meisn. (jointweed). Common;
in low dune areas. CZ 483, 562, 568, 626, 641; Crow 2496.

Polygonum scandens L. (climbing false buckwheat).
Frequent; on shrubs in thickets and on edges of sunken
forests. CZ 440, 517, 617, 643.

PRIMULACEAE (Primrose Family)

Lysimachia quadrifolia L. (whorled loosestrife). Common;
along roadside. CZ 156.

Trientalis borealis Raf. (star flower). Occasional; in
sunken forest. CZ 54.

RHAMNACEAE (Buckthorn Family)

Rhamnus frangula L. (buckthorn). Occasional; in sunken
forest. CZ 231.

ROSACEAE (Rose Family)

Amelanchier canadensis (L.) Medic. (shadbush). Common;
in sunken forests and in thickets. CZ 12, 22, 59, 65, 221,
232, 496, 590.

Amelanchier stolonifera Wieg. (shadbush). Common; in
sunken forest and in thickets. CZ 24, 34, 596, 614, 645.

Aronia arbutifolia (L.) Ell. (red chokeberry).
Occasional; in wet swale and sunken forests. CZ 18, 43,
53, 213, 316.

Page 19

Aronia prunifolia (Marsh.) Rehder (purple chokeberry).
Common; in thic ts, wet swales, and edge of sunken forsts.
CZ 64, 501, 514, .577, 660; Crow 2492.

Crataegus chrysocarpa Ashe. (hawthorne). Frequent; in
sunken forests and in thickets. CZ 2, 40, 299, 393, 443.

Fragaria virginiana Duchesne (wild strawberry). Local;
in sandy area at edge of thicket behind ridge of dune.
McDonnell 944.

Prunus maritima Marsh. (beach plum). Abundant; on edges
of sunken forests and thickets. CZ 16, 41, 126, 224, 263,
320, 494, 583, 591, 610, 646; Crour-25-6-5. - - '

Prunus pensylvanica L. (pin-cherry). Uncommon; in sunken
forest. CZ 23.

Prunus serotina Ehrh. (black cherry). Common; in sunken
forests and in thickets. CZ 25, 56, 63, 66, 70, 227, 239,
392, 595, 612, 621, 636; Crow 2501.

Prunus virginiana L. (choke-cherry). Frequent; in sunken
forests. CZ 5, 30, 33, .44, 208, 259; Crow 2504.

Rosa virginiana Mill. (low rose). Common; in thickets,
sunken forests, and low dune areas. CZ .109, 129, 155, 235,
273, 516, 618, 624, 649.

Rubus allegheniensis Porter (common blackberry).
Occasional; edge of sunken forest. CZ 228.

Rubus idaeus L. var. strigosus (Michx.) Maxim. (red
raspberry). Occasional; edge of sunken forest. CZ 79.

Spiraea latifolia (Ait.) Borkh. (meadow sweet).
@5_c@casional; in low dune area and edges of wet swales and
sunken forests. CZ 181, .236, 301, 382.

Spiraea tomentosa L. (hardhack) Occasional; in
thickets. CZ 500.

RUBIACEAE (Madder Family)

Galium aparine L. (spring-cleavers). occasional; in
sunken forests. CZ 85, 616.

Houstonia caerulea L. (bluets). Uncommon; edge of sunken
forest. CZ 106.

SALICACEAE (Willow Family)

Populus tremuloides Michx. (trembling aspen, small-toothed
aspen). Common; in thicket area. CZ 589.

Page 20

SAXIFRAGACEAE (Saxifrage Family)

Ribes hirtellum Michx. (common gooseberry). Common; on
edge of sunken forest. CZ 28, 229;@ McDonnell 931.

SCROPHULARIACEAE (Figwort Family)

Linaria. canadensis (L.) Dumont (old-field toadflax).
- r-
occasional; in low dune area and along roadside. CZ .62,
387.

SOLANACEAE (Nightshade Family)

Solanum dulcamara L. (nightshade). Frequent; in sunken
forests. CZ 104, 154, 225., 261, 394.

Solanum nigrum L. (black nightshade). Uncommon; in
sunken forests. CZ 615.

VITACEAE (Grape Family)

Parthenocissus quin5uefolia (L.) Planch. (Virginia
creeper). Common; in sunken forest and thicket areas. CZ
305, 395, 499, 592, 609, 620, 638; Crow 2493.

Vitis labrusca L. (fox grape). Common; in sunken forest.
CZ 37.

Vitis riparia Michx. (frost grape). Uncommon; in thicket
area, CZ 585.

Page 21

MONOCOTS

CYPERACEAE (Sedge Family)

Carex silicea Olney (sedge). Occasional; in low dune
areas and sunken forest. CZ 274, 573; Crow 2510.

Carex pensylvanica Lam. (sedge). Abundant; on edge of
sunken forests and in low dune areas. CZ 21, 42, 75.

*Cyperus grayii Torr. (Gray's sedge). Frequent; in low
dune area. CZ 219, 306, 383, 384, 390, 485, 5610, 566; Crow
_S
2502; Stork 2 0.

Cyperus filiculmis Vahl (sedge). Common; in low dune
area and roadside. CZ 220, 325, 367, 377, 409, 447, 451,
455, 458, 467, 4711 473_05_@T_8, 5T-O,5T-7. -

Scirpus atrocinctus Fern. (dusky wool-grass). Local; wet
swale. CZ 215.

JUNCACEAE (Rush Family)

Juncus balticus Willd. (rush). Common; in wet swale. CZ
-55, 47, 214, 269.

Juncus gerardi Loisel. (black-grass). Abundant; in salt
marsh. Cz 267, 653.

Juncus Oakes and Tuckerm. (Greene's rush).
occasion thicket. CZ 505.

Juncus tenuis Willd. var. tenuis (rush). Local; wet
Tw-ales. CZ 315, 317, 399, 401, 402, 579.

JUNCAGINACEAE (Arrow-grass Family)

Triglochin maritima L. (arrow-grass). Occasional; in wet
swales in low dune areas. CZ 72.

LILIACEAE (Lily Family)

Maianthemum. canadense Desf. (false lily-of-the.-valley).
Kbundant; in sunken forests. CZ 1, 52, 96, 512.

Polygonatum pubescens (Willd.) Pursh. (Solomon's seal).
Uncommon; in sunTe-nforest. CZ 11.

Smilacina stellata (L.) Desf. (false Solomon's seal).
Common; in sunken forests and thickets. CZ 19, 39, 98,
110, 238, 510, 586.

Page 22

POACEAE/GRAMINEAE (Grass Family)

Agrostis alba L. (redtop). Occasional; in low dune area.
CZ 650.

Agrostis scabra L. (ticklegrass). Frequent; in low dune
area. CZ 74.

Agropyron repens (L.) Beauv. (quack-grass). occasional;
in low dune area and edge of thickets. CZ 197, 268.

*Ammophila breviligulata Fern. (beach grass). Abundant;
in low dune areas. CZ 128, 266, .319, 487, 547; Crow 2508;
Storks 233.

Andropogon scoparius Michx. (little bluestem). Common;
along roadside and low dune areas, edges of thickets and
sunken forests. CZ 386, .442, 507, 518, 625, 655.

*Aristida tuberculosa Nutt. (seabeach needle grass).
Locally abundant; on roadside, west side of Rt. 1A in dry
sand, and in low dune area, especially in northern portion
of study area. CZ 385, 437, 479, 565; Crow 2513; Storks
231; Hodgdon and ff_te,@'1_elZ494.

Bromus tectorum L. (downy chess). Common; in sunken
forest and low dune areas. CZ 38, 61, 130, 223, 260, 391.

Calamagrostis canadensis (Michx.) Nutt. (blue-joint).
Common; edge of sunken forest. CZ 60, 262.

Danthonia spicata (L.) Beauv. (poverty-grass). Common;
gouthern low dune area. CZ 265.

Digitaria ischaemum (Schreb.) Muhl. (small crabgrass).
Common; on distuTb-ed sites, particularly along road across
dune and around foundation of abandoned building. McDonnell
945.

Digitaria sanguinalis (L.) Scop. (crabgrass). Occasional;
IT low dune areas. CZ 441, 651.
along roadside and in

Distichlis spicata (L.) Greene (spike-grass). Common; in
salt marsh. CZ 379.

Festuca ovina L. (sheep's fescue). Occasional; in low
dunes areas. Crow 2511.

Festuca rubra L. (red fescue). Frequent; on edge of
sunken forest. CZ 57.

Panicum lanuginosum Ell. var. fasciculatum (Torr.)
Fern. (panic grass). occasional; in low dune area. CZ
73.

Page 23

Phleum pratense L. (timothy). Occasional; on edge of
sunken forest. CZ 202.

Poa pratefisis L. (Kentucky bluegrass Occasional; edge
'Z@-fsunken forest. CZ 24, .264.

Puccinellia maritima (Huds.) Parl (alkali-grass). Common;
272, 370, 372, 373.
in salt mars CZ 89, 222

*Puccinellia paupercula (Holm.) Fern. and Weath.
var. alaskana (Scribn. and Merr.) Fern. and Weath.
(alkaTi@-grass). Occasional; edge of salt marsh. CZ .633.

Spartina alterniflora Lo,isel (saltwater cordgrass).
Common; short form in wetter areas of high salt marsh. CZ
488; McDonnell 961.

Spartina patens (Ait.) Muhl. (salt-meadow grass, salt
marsh grass). Common; in salt marsh. CZ 210, 271, 375.

Page 24

ENDANGERED SPECIES

In the fall of 1978 a report prepared at the University

of New Hampshire entitled Rare and Endangered Plant Species

in New Hampshire (Storks and Crow, 1978) was published

enumerating 398 vascular plant taxa which were regarded as

sufficiently rare in the state to warrant their protection

through habitat preservation. Of these, a total of 37

species (9%) are coastal (including Great Bay estuarine

system), some of which are known only from a single town or

single site (Crow and Storks, 1980).

The coastal region has experienced continued intense

pressure from developmental interests. One heavily impacted

area is the Seabrook dune site. Nine species found at the

dunes are listed. Five are regarded "endangered," two are

given "threatened" status and two are treated as "rare"

(Crow and Storks, 1980; Storks and Crow, 1978).

----------
While the rare and endangered plants species list does not
enjoy official recognition by State law, the list was adopted
by Governor Gallen's Advisory Council on Growth. Its Natural
Areas Committee recommended the establishment of a program to
protect rare, threatened and endangered plant species in New
Hampshire (OSP, 1981) and The Nature Conservancy, working under
contract with the Office of State Planning, viewed the list as
a key element of their proposed N. H. Natural Heritage Program
(TNC,1980).

Page 25

Endangered

Arenaria peploides var. robusta
Aristida tuberculosa
Cyperus grayii
Hudsonia tomentosa var. tomentosa
SaIicorn'la virginica

Threatened

Ammophila breviligulata
Salicornia bigelovii

Rare

Artemisia caudata
Puccinellia paupercula var. alaskana

All nine are typically restricted to the coastal sand

dune or salt marsh habitat. Notes on relative abundance,

distribution and location in the Seabrook backdune community

are provided for each. They are presented in alphabetical

order.

Ammophila breviligulata beach grass

Poaceae/Gramineae

This robust perennial beach grass is the dominant
it species in the dunegrass vegetation type in the low dune

area at the Seabrook study site. It also occurs on the

foredune at Seabrook Beach and in several sandy areas along

the New Hampshire coast, especially along roadsides and near

residential areas where the natural vegetation has managed

to persist. Ammophila breviligulata is critical to the

stabilization of the dunes. The Seabrook dune population of

this species is the most significant site in the state.

Page 26

Arenaria peploides seabeach sandwort

Caryophyllaceae

Only one site, consisting of a single plant, was found

on the New Hampshire coast during the 1982 field season.

This particular plant is located at the north end of the

backdune where Cross Beach Road meets Route 1A. It lies

just above the strand line, very close to the pavement of

Route 1A. This site was observed in October 1982, but was

originally discovered by Frank Richardson in 1973 (Breeding

et al., 1974; Richardson, pers. comm.). The Seabrook site

is particularly significant since it represents the only

occurrence in the state. The species appears to be

declining in Massachusetts; it has not been collected on

Plum Island since 1915 and may have been extirpated there

(McDonnell, 1979a).

Aristida tuberculosa seabeach needle grass

Poaceae/Gramineae

Seabeach needle gras grows scattered throughout the low

dune area. It iss locally abundant on the northwest side of

the backdune and along the side adjacent to Route 1A. In

addition, it is frequently present on vacant lots and

roadsides in the residential neighborhoods (the original

interdune area) at Seabrook Beach. This species, restricted

to only one town in New Hampshire, is also listed on the

regional list of rare and endangered plants of New England

Page 27

(Crow et al., 1981). It is most apparent in late August by

the conspicuously twisted glumes on the fully mature flower

spike.

Artemisia caudata wormwood

Asteraceae/Compositae

This member of the daisy family is occasionally found
along the edges of the thickets 'and on the northern fringe

of sunken forest No. 2. Outside of the study area, it is

frequent along the New Hampshire coast in sandy sites,

especially on the foredune at Seabrook Beach. This

deep-rooted biennial grows for one season as a rosette of

finely dissected green leaves, then puts forth a tall
40 inflorescence of inconspicuous flowers the second year. The

entire plant dies at the end of the second year. It is

readily recognized throughout the growing season.

Cyperus grayii Gray's sedge

Cyperaceae

This member of the sedge family is restricted to the

Town of Seabrook, where it grows on the low dunes of the

study area. It occasionally grows on the foredune and along

sandy roadsides at Seabrook Beach. It can only be

distinguished from another similar, but common sedge, when

it is in flower.

Page 28

Hudsonia tomentosa var. tomentosa beach heather

Cistaceae

Hudsonia tomentosa var. tomentosa, found only in two

towns in the state (Seabrook and Rye), occurs in both the

foredune and backdune and occasionally in vacant lots in the

residential area of Seabrook Beach. In the study area,

Hudsonia tomentosa forms large mats on the low dunes where

it is well adapted to shifting sands. McDonnell (1981)

found this species exhibited greatest sensitivity to

trampling of all the dune flora of Plum Island. When this

low, blue-green leaved plant blooms in June, bright yellow

flowers carpet portions of the low dune area. Closely

related Hudsonia tomentosa var. intermedia occurs in only 3

towns in central New Hampshire.

Puccinellia paupercula alkali-grass

Poaceae/Gramineae

This grass of saline sites occurs scattered on the high

salt marsh, particularly in the drift-line area. It is

sometimes difficult to distinguish this species from

depauperate plants of its close relative Puccinellia

Al maritima.

Page 29

Salicornia bigelovii glasswort

Chenopodiaceae

This species is typically a salt marsh plant and is

occasionally found on the New Hampshire coast in highly

saline pannes on the high marsh. A few plants were found in

a low area at the north end of the Seabrook dunes study area

(south of Cross Beach Road and adjacent to Route 1A). This

tiny annual is very inconspicuous most of the year and best

recognized in late summer when it reaches its maximum

growth.

Salicornia virginica woody glasswort

Chenopodiaceae

This species of Salicornia is locally abundant at the

edge of the salt marsh bordering the north side of Cross

Beach Road and northward along the western side of Route 1A

to the nearby commercial properties. It is readily

recognized throughout the growing season.

Page 30

SITE EVALUATION

Three of the nine rare and endangered species, Aristida

tuberculosa (seabeach needle grass), Arenaria peploides

(seabeach sandwort), and Cyperus grayii (Gray's sedge), are

restricted to the dune community at Seabrook. Although

locally abundant at Seabrook dunes, Aristida tuberculosa is

considered endangered not only for New Hampshire, but for

the New England region as well (Crowet al., 1981). Only a

single plant of Arenaria peploides was found at the north

end of the backdune. It represents the only presently known

site for New Hampshire.

The population of Hudsonia tomentosa (beach heather) at

Seabrook is the largest coastal stand in New Hampshire.

Until a small site was located in the Town of Rye during the

course of this project, it was thought to occur only in

Seabrook.

The other five rare elements are restricted to the

coastal region but occur in a few other coastal towns.

However, the Seabrook populatio n of Ammophila breviligulata,

the beach grass, is the most significant (best developed,

most natural) in the state. Artemisia caudata (wormwood) is

likewise best represented in Seabrook. The salt marsh

rarity Salicornia bigelovii '(Bigelow's glasswort) is

somewhat scattered in the extensive salt marsh ecosystem in

coastal New Hampshire. Its even rarer relative, Salicornia

virginica (woody glasswort) is much more restricted; the

Page 31

population at the Seabrook dune study site was found to be

the largest (albeit still rather small) along the New

Hampshire coast.

This underscores the importance of the dune community

at Seabrook as a key element in the preservation of some of

New Hampshire's rare flora. But the Seabrook community is,

itself, threatened with extinction, and as it goes, so goes

the last remnant of a natural dune system for the entire

state of New Hampshire.

Perhaps the major threat to these populations is the

impact of four-wheel drive and off-road vehicles. Access

points from Route 1A and Cross Beach Road provide ent'rance

to the many trails and paths that criss-cross the dunes. A

recent town map depicts a road, Old Beach Road, transecting

the dunes from Route 1A and running along the western

boundary.

The damage done by these vehicles is readily visible

(figs. 4, 5). The vehicles are driven up over small dunes,

tearing up vegetation and exposing the dunes to wind

erosion. A walk throught the dunes usually reveals a number

of sites where vehicles have become stuck in the sand and

great efforts were used to extract them. Large ruts from

spinning tires are indicative of these sites.

Fig. 4. Four-wheel drive vehicle churning up sand of dunes.
1979. Photo by Garrett E. Crow

_Fig. 5. Vehicle damage on dunes. 1982.
Photo by Garrett E. Crow

IF
mmm@ &ARM

Page 32

By far, the greatest ecological damage has been done to

the dunegrass vegetation, in the low dunes area, the area

where most of the rare species grow. While tall trees and

shrubs of the sunken forests and thickets bar entrance into

these areas, the loose sand created by vehicle damage

destabilizes the dune system causing blowouts and dune

movement, eventually resulting in the burial of whole sunken

forests. Early stages of this can be readily observed at

Sunken Forest No. 2.

The following recommendations are offered:

Recommendation 1. It is essential to halt the continuation
of damage to the dunes caused by off-road vehicles. Fencing
off the areas may not be practical, but pilings spaced to
prevent vehicle access to the dunes at strategic locations
could be installed. Signs announcing prohibition of
vehicles will also be needed. Cooperation of the Seabrook
police to enforce the prohibition is essential.

Recommendation 2. Further real estate development along the
edge of the dunes should be prohibited in order to maintain
the integrity of the backdune community.

Recommendation 3. Efforts should be made to establish the
backdune community as a "Seabrook Dunes Natural Preserve"
under the New Hampshire Natural Areas Program to provide
protection of this site, with its unique flora and rare
plants. The site should also be monitored by a group
designated by the Natural Areas Program, such as the Society
for the Protection of New Hampshire Forests or The Nature
Conservancy.

All nine of these rare species are strictly dune or

salt marsh plants and their existence is dependent on this

unique habitat. Embodied in the federal Endangered Species

Act of 1973 is the important concept of Critical Habitat.

If the rare and endangered plants of the coastal zone are to

survive we must also take an ecosystems approach. It is

Page 33

impractical to provide protection for every site in New

Hampshire were rare plants or animals occur. Thus, when

several rare elements occur at a single locality it is

indicative of a unique and very valuable habitat and a high

priority should be placed on protection for the whole

ecosystem on which the organisms depend for their survival.

Therefore, preservation of the remaining Seabrook dunes

community, with its nine rare species, must be seriously

considered by the State of New Hampshire and the Town of

Seabrook.

Page 34

LITERATURE CITED

Breeding, C. H. J., F. D. Richardson, S. A. Pilgrim. 1974.
Soil survey of New Hampshire tidal marshes. N. H.
Agric. Exp. Sta. Res. Rep. 40.

Crow, G. E., W. D. Countryman, G. L. Church, L. M. Eastman,
C. B. Hellquist, L. J. Mehrhoff, and I. M. Storks.
1981. Rare and endangered vascular plant species in
New England. Rhodora 83: 259-299.

Crow, G. E. and I. M. Storks. 1980. Rare and endangered
plants of New Hampshire: a phytogeographic viewpoint.
Rhodora 82: 173-189.

Fernald, M. L. 1950. Gray's manual of botany. Corrected
printing, 1970. D. Van Nostrand Co., New York.

Gleason, H. A. and A. Cronquist. 1963. Manual of vascular
plants of northeastern United States and adjacent
Canada. D. Van Nostrand Co., New York.

McDonnell, M J. 1979. The vascular flora of Plum Island
Essex County, Massachusetts with an analysis of the
impact of human trampling on coastal dune vegetation.
M.S. thesis, University of New Hampshire, Durham, NH.

McDonnell, M. J. 1979a. The flora of Plum Island, Essex
County, Massachusetts. N. H. Agric. Exp. Sta.
Bull. 513.

McDonnell, M. J. 1981. Trampling effects on coastal dune
vegetation in the Parker River National Wildlife
Refuge, Massachusetts, USA. Biol. Conserv.
21: 289-301.

OSP. 1981. The final report of the Govenor's Advisory
Council on Growth. N. H. Office of State Planning,
Concord, NH.

Storks, I. M. and G. E. Crow. 1978. Rare and endangered
vascular plant species in New Hampshire. The New
England Botanical Club in cooperation with the U. S.
Fish and Wildlife Service [Region 5, Newton Corner,
MA).

TNC. 1980. A New Hampshire Natural Heritage Program: an
interim plan. The Nature Conservancy, Arlington, VA.

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