Flora of Martha's Vineyard (2008)

The Flora of Martha’s Vineyard 

by Stephen A. Spongberg, Ph. D.

In its simplest form, the flora of any given region consists of a systematic listing or inventory of the diversity of plants that grow in the region without cultivation. These include both the indigenous or native species as well as those taxa that have been introduced through the activities of man or as a consequence of his activities; these latter plants have become naturalized, sometimes with a very negative impact on the habitats and taxa of the native flora. In a more expanded form, a flora includes complete descriptions of the taxa, illustrations, keys for identification, and notes on ecology, distribution, flowering and fruiting periods (phenology), and other aspects of the natural history of the species comprising the flora, sometimes also including their ethnobotanical uses. Unfortunately, the present contribution falls into the first category, although it is hoped that a more complete flora – including keys for identification as a minimum –  will be available in the future.

By contrast with its flora, the vegetation of an area consists of the mosaic of plant communities that occupy the various habitats that exist within the region under study. These communities and their species composition represent a dynamic and ever-changing interaction between biotic and physical environmental factors. With its pine and scrub- oak forests of the outwash plain and its low-canopied, often windswept oak and beech forests up-island, the vegetation of Martha’s Vineyard is undoubtedly the most evident factor and single greatest contributor to the combination of features that help to create the “magic” of the island. 

The plants included in the accompanying checklist of the Martha’s Vineyard (and Dukes County) flora – the so-called vascular plants – are differentiated from groups of lower plants (treated elsewhere in this volume) by the presence of vascular tissues, namely xylem and phloem, in the plant body. The development of these water-conducting tissues was a major evolutionary advancement that enabled taxa of these plant groups to occupy non-aquatic habitats, to become adapted to life on land, and to acquire greater size than would otherwise have been possible.  

Following the system of Margulis and Schwartz (1998), the vascular plants included here represent five phyla of Kingdom Plantae. These are Lycophyta, the club mosses, Sphenophyta, the horsetails, Filicinophyta, the ferns, Coniferophyta, the conifers, and Anthophyta, the angiosperms or flowering plants, which are further subdivided into two major groups or subphyla, the dicotyledons and the monocotyledons. Collectively, the first three phyla have traditionally been referred to as the pteridophytes or ferns and fern allies. Members of these phyla lack true flowers and reproduce through the production of spores. Plants of both the Coniferophyta and Anthophyta (the conifers and angiosperms), by contrast, produce seeds, and the members of the latter group develop true flowers. 

The pteridophytes are all of ancient lineage and are well represented in the fossil record. Fossils of the club mosses date back some 400 million years to the Devonian. During the Carboniferous club mosses of treelike stature were commonplace and contributed to the coal strata formed during that time. These ancient giants died out some 280 million years ago, but the group has continued to exist and is represented in our temperate flora by the four genera included in the family Lycopodiaceae in the checklist.

Like the club mosses, the horsetails flourished during the Carboniferous. Today, however, only fifteen species comprise the genus Equisetum, today’s sole representative of the Phylum Sphenophyta. Like the first club mosses, the ferns first appeared in the fossil record during the Devonian, some 400 million years ago. But unlike the other pteridophytes, the ferns are still well represented in the modern floras in temperate and particularly topical regions of the world, especially in tropical montane forests. While about 200 species of ferns are native to North America, world-wide upwards of 10,000 species have been described and placed in over 200 genera, which have been grouped in between 25 and 35 families.  

Of five major plant groups that produce seeds as a reproductive strategy, four groups have traditionally been included under the heading of gymnosperms, a term signifying “naked seeds.”  In our flora, the gymnosperms are represented by only one of the four phyla, Phylum Coniferophtya, the conifers, the largest and most familiar group that produce naked seeds. In the Coniferophyta, seeds are produced in a reproductive structure termed a strobilis, familiarly known as a cone. By contrast, the angiosperms produce seeds within the confines of a protective carpel or ovary in a structure known as a flower; all angiosperms are included in the Phylum Anthophyta.

Gymnosperms are all woody plants – trees and shrubs – and all have only tracheids in the xylem, one of the vascular tissues. By contrast, some angiosperms are woody trees and shrubs as well as woody climbers (lianas), but many others lack woody tissues and are herbaceous. Furthermore, the angiosperms include vessels as well as tracheids in the xylem, a combination of cell types that is more efficient than tracheids alone in water transport within the plant.

The first conifers in the fossil record appeared in the Carboniferous, some 300 million years ago, and the pines and other modern genera made their appearance during the late Triassic period of the Mesozoic era, some 170 million years ago. Still a dominant group in modern floras, the conifers consist of seven families and 60 to 65 genera with upwards of 600 species. The conifers are characteristic component of the boreal forests of the Northern Hemisphere as well as the montane forests of western North America, while on the Vineyard, Pinus rigida, the pitch pine, and Juniperus virginiana, red cedar, are signature trees that contribute much to the character of the island’s landscape.

Two conifers, Sequoia sempervirens (the California redwoods – the tallest trees known) and Sequoiadendron giganteum (of the Sierra Nevada, the largest known trees) are worthy of note. Additionally, individuals of Pinus longaeva of the White Mountains in California are thought to be the oldest extant organisms with ages between four and five thousand years.

The angiosperms or flowering plants (Phylum Anthophyta) are – relatively speaking – new-comers. The earliest fossils attributable to an angiospermous plant appear in the Jurassic, about 140 million years ago, in the early Cretaceous Period toward the end of the Mesozoic Era. Some of the earliest fossil flowers, which closely resemble those of modern-day magnolias, are about 120 million years old.  Soon after their appearance, however, angiosperms became the dominant land plants, a position they continue to occupy today. It is now estimated that over 230,000 species are known and that upward of a million species might be described if angiosperm diversity was thoroughly studied. Known species have been placed in upwards of 400 families and over 12,500 genera, and the diversity of flowering plants has customarily been divided into two major subgroupings or subphyla, the dicotyledons (or dicots) and monocotyledons (or monocots). While these two groups may not reflect natural relationships, the dicots (ca. 170,000 species) are distinguished by two cotyledons or seed leaves, while monocots (ca. 60,000 species) produce seeds with a single seed leaf or cotyledon. Additionally, the leaf venation of monocots is parallel while that of dicots is netted, floral parts in monocots are generally in threes, while those of dicots are in fours or fives, and monocots fail to produce woody tissues while many dicots are trees, shrubs, and woody climbers (vines). 

While the conifers are strictly wind pollinated (as Vineyard residents realize each June, when every breeze carries its “rain” of pine pollen), and while some angiosperms are also wind pollinated, most flowering plants have evolved a host of adaptations to animal (primarily insect) pollination. Overall, the angiosperms or flowering plants have become adapted to almost every conceivable ecological niche and habitat and have successfully claimed the planet earth as their realm.  

The Numbers

One thousand two hundred forty-five (1,245) taxa are recorded in the checklist as comprising the flora of Martha’s Vineyard and Dukes County. These include species, subspecies, varieties, and interspecific hybrids. These taxa represent 495 genera in 133 vascular plant families. Of the total, 372 or 29.8% are introduced and not indigenous to the area. These figures are slightly higher than the 1,016 taxa recorded for the island in the Flora of Martha’s Vineyard (Swanson & Knapp, 1999). In that flora, 290 taxa are listed as introduced, but the percentage of the total (28.5%) is essentially equivalent to the present tally for introduced taxa. The current statistics are summarized in Table 1.

Table 1.   Statistics for the Flora of Martha’s Vineyard

 

                                        Families             Genera            Taxa          Introductions

 

Phylum Lycophyta                     2                          5                 8                        0

Phylum Sphenophyta                1                          1                 1                        0

Phylum Filicinophyta                  9                        15                28                      0

Phylum Coniferophyta                2                         6                  3                       9

Phylum Anthophyta

  Dicots                                      95                     350              841                  308

  Monocots                                24                     118              345                     55

Total                                         133                     495            1245                  372

By comparison, the flora of the neighboring island of Nantucket has been calculated to consist of a total of 1,265 taxa, of which 489 (39%) are introduced (Sorrie & Dunwiddie, 1996), while Sorrie and Somers (1999) treat a total of 1,503 taxa for Cape Cod (Barnstable County), of which 495 (33%) are introduced. Earlier, Svenson and Pyle (1979) accounted for a total of 1,273 taxa for the same area. Totals for the  Commonwealth of Massachusetts yield 3,119 taxa of which 1,349 (43%) are introduced (Sorrie & Somers, 1999), while the entire New England region (including adjacent New York State) supports a flora of 4,133 taxa (Magee & Ahles, 1999), almost four times the number comprising the Vineyard list.

What is surprising in these comparisons is not that the Vineyard supports a smaller flora than Cape Cod but that the known Nantucket flora is larger (by 20 taxa) than that of the Vineyard.  It would be expected that the Vineyard, with its larger area and seemingly greater diversity of habitats, would support the larger flora.  It is probable that this discrepancy will be resolved as further taxa are added to the Vineyard checklist through additional field studies. In this regard (as Tom Chase of the Nature Conservancy has suggested), it would be a useful exercise to list those taxa not found in the Vineyard flora but recorded for Nantucket and Cape Cod; keen observers of the Vineyard flora could then be on the lookout for these plants inasmuch as they are likely candidates for inclusion in the Island’s flora.

While the Vineyard flora is not distinguished by any endemic taxa, Amelanchier nantucketensis, Nantucket shadbush, described from Nantucket in 1919 by Bicknell, is thought by some to be restricted to Nantucket, Martha’s Vineyard, and some of the adjacent, smaller islands (Magee & Ahles, 1999). The status of this taxon, however, depends upon taxonomic interpretation, and Sorrie & Sommers (1999), defining a broader taxon, attribute to it a wider range that extends westward across the Commonwealth to the Berkshires.  Corema conradii, broom crowberry, Helianthmum dumosum, bushy rockrose, and Pityopsis falcata, sickle-leaved aster, are taxa of limited distributions and narrow ecological requirements as are other species listed in the register of those species considered Endangered, Threatened, and of Special concern in Massachusetts as defined in Massachusetts General Law Chapter 131A. Species listed in these categories are protected from being collected or taken under the Massachusetts Endangered Species Act. The list of plants protected in Masschusetts can be viewed on the Natural Heritage and Endangered Species Program website, here.

Introduced and Invasive Taxa

Many of the introduced plants in the Vineyard flora have become so commonplace that many people think of them as components of the native flora. Rosa rugosa, salt-spray rose, is an unparalleled example of an Asian species first introduced into North America in the middle of the nineteenth century as a garden ornamental that has become completely naturalized on the coastal dunes along the Atlantic coast of eastern North America (including the Vineyard) as well as in similar habitats in the Great Lakes region. Artemisia stelleriana, dusty miller, is another plant of sandy beeches that is so familiar that most observers think it a native, not a naturalized, exotic plant.  Likewise, Elaeagnus umbellata, autumn olive, and E. angustifolia, Russian olive, are characteristic shrubs of old fields and thickets where by virtue of their numbers alone they appear to be components of our native flora. And Robinia pseudoacacia, black locust – sought-after by local craftsmen for its durable wood – is not native to the island despite the fact that it is not uncommon in Vineyard woodlands. The completely naturalized and ubiquitous Celastrus orbiculatus (Oriental bittersweet), ironically, is decidedly more completely adapted to the Vineyard environment than its American congener, Celastrus scandens (American bittersweet), which is rare on the Island.  

Several of the introduced species in the Vineyard flora have become invasive and constitute a threat to native habitats where, because they can out compete native taxa, they displace native, often rare, species. Attributes of non-native species that have become or may become invasive include the following characteristics, which have been outlined by Weatherbee et al. (1999). Germination, growth, and maturation to flowering are rapid. The plants of the species spread quickly either through efficient seed dispersal or by vegetative means, or both, and the onset of flowering is generally early in the season and continues for a prolonged period. Insofar as the species is a non-native plant, it is likely that diseases or natural pests or other biotic factors that function to check its growth or success in its native range are not present in its new habitats. Moreover, invasive species tend to have wide ecological tolerances that enable colonization of a spectrum of habitats. Most, additionally, tend to be perennials that are difficult to eradicate either physically or by chemical or other mechanisms. Frequently, the number of individuals is increased when attempts are made to physically remove the plants. 

As is the case with the palette of agricultural weeds, the majority of which are of Eurasian origin and have come to the Island with man, his domesticated farm animals, or as a consequence of his or her activities, most invasive species gain their first footholds in disturbed soils and/or habitats. This is a particularly easy phenomenon to notice firsthand as one inspects the plants occupying roadsides, the edges of agricultural land or fallow fields, construction sites, and even lawns and vegetable and flower gardens, where every homeowner and amateur horticulturist spends a fair amount of time coping with the problem of weeds.

Among the introduced species in the Vineyard flora that are known to be invasive are the following:

Ailanthus altissima – tree-of-heaven 

Alliaria petiolata – garlic mustard

Ampelopsis brevipedunculata – porcelain berry

Celastrus orbiculata – bittersweet 

Centaurea biebersteinii – bushy knapweed

Elaeagnus umbellata & E. angustifolia – autumn and Russian olives, respectively

Linaria dalmatica – Dalmatian toadflax 

Lonicera japonica – Japanese honeysuckle 

Lonicera morrowii – Morrow’s honeysuckle 

Lythrum salicaria – purple loosestrife 

Miscanthus sinensis – miscanthus – 

Polygonum cuspidatum – Japanese knotweed

Rhamnus cathartica & R. frangula – common and glossy Buckthorn, respectively

Robinia pseudoacacia – black locust

Rosa multiflora – multiflora rose

Species in our native flora may also behave like invasive species and can be equally troublesome. The following species are nominated native invasives, and the list could undoubtedly be expanded:

Phragmites australis – common reed   

Rhus copallinum var. latifolia  – winged sumac

Smilax rotundifolia – catbrier 

Toxicodendron radicans – poison ivy  

The introduction of additional exotic species to the island will surely continue as new garden ornamentals are tested under Vineyard climatic conditions. Likewise, the accidental and unintentional introduction of known weeds and invasives from other regions will in all likelihood occur. It behooves anyone knowingly engaged in the introduction of a new species to the island – for whatever purpose – to be cognizant of the possibility that the new plant might have the potential to become naturalized and invasive. Early detection of these propensities might help prevent that unfortunate possibility.

The Origin & Phytogeographic Relationships of the Vineyard Flora

The flora of Martha’s Vineyard (as well as that of Cape Cod and the neighboring islands) is a product, like the Vineyard itself, of the consequences of the Pleistocene and the succeeding periods of post-Pleistocene history. As John Fogg pointed out when he was considering the origins and geographic affinities of the flora of the Elizabeth Islands, to do so is to consider the flora of the Atlantic Coastal Plain and that of the “morainal deposits of which most of southeastern Massachusetts is composed” (Fogg, 1930, p. 167). Based on the evidence he was able to bring to bear on the question of the Vineyard flora, Fogg was of the opinion that it “is far from being closely related to that of the southern coastal plain,” (Fogg, 1930, p. 175) but rather, is more closely allied to continental and northern floras. This opinion was maintained by Ogden (1958), who based his studies on more nearly complete floristic data than was available to Fogg. Both Fogg (76 years ago) and Ogden (48 years ago) noted and lamented the fact that the Vineyard had not received the attention of botanists that had been accorded Nantucket and the Elizabeth Islands, for which local floras were then available. This impediment to the analysis of phytogeographical relationships, however, has now been overcome with the work of the Martha’s Vineyard Sandplain Restoration Project (Swanson & Knapp, 1997) and Sorrie and Somers (1999), as well as the New England floras produced in the intervening years by Seymour (1969) and Magee and Ahles (1999). While additional fieldwork is still called for on the Vineyard, and an exhaustive phytogeographical analysis of the Vineyard flora remains to be undertaken, we are in a far better position to comment on general relationships than were either Fogg or Ogden. But to attempt to understand these relationships, a review of the Pleistocene and post-Pleistocene (Quatenary) floristic “migrations” as they are now understood in broad outline (and based, in part, on Ogden’s palynological studies) is outlined briefly below.

The location of the Vineyard on the continental shelf places it at the very northern reaches (or just north) of the Atlantic Coastal Plain floristic province, and the structure of the island, consisting as it does of morainal hills and outwash plain, gives the island unexpected elevation. To my thinking, the island is somewhat akin to a monadnock, which rises above an otherwise more-or-less level and featureless plain. The presence of the morainal hills in the so-called up-island areas of the Vineyard has provided habitats for a relic northern or boreal floristic element that speaks to the evolving character of the flora itself. And it was these habitats and the plants that grow there that influenced Fogg’s comments that “it seems evident that the long line of high hills which flanks the north shore from Menemsha to West Chop supports a flora of northern or continental nature. Several plants were found here, in the richer soils of the wooded slope, which are either absent from or far from common in southeastern Massachusetts, and it seems very likely that careful search will disclose many more things of this nature.” (Fogg, 1930, pp. 175, 175.)  Fogg and his mentor at the Gray Herbarium, Professor M. L. Fernald, also visited Aquinnah, and Fogg noted that they were “unable to escape the conviction that the flora dealt with was continental rather than coastal in character. Time and time again the impression was borne home that the countless southern plants which form the primary element in the flora of the middle part of Cape Cod were conspicuously absent” (Fogg, 1930, p. 175). While Fogg suggested that the flora of the down-island regions of the Vineyard may contradict his impressions, he apparently lacked first-hand information for the flora of that area. 

In an attempt to explain the presence of northern elements in the Vineyard flora, it will be helpful to recall that during the Pleistocene, when enormous quantities of water were captured in the massive continental ice sheets that covered much of North American and Europe, a vast expanse of the North American continental shelf (of which the coastal plain is currently the exposed remnant) was exposed and available for colonization by vegetation. And as the glaciers advanced southward and the temperatures cooled as a consequence, the zones of the so-called Arctotertiary vegetation (the great belt of very diverse temperate and boreal plant communities that encircled the northern hemisphere prior to Pleistocene glaciation) was gradually displaced southward and out onto the broad expanse of exposed continental shelf.

When the last advance of the Wisconsin glaciations had deposited on a pre-existing network of ridges the morainal deposits that were to become up-island Martha’s Vineyard, and the glacial melt-waters carried the associated sand and gravels that would form the down-island outwash plain, the climate began to ameliorate, and the fragmented remnants of Arctotertiary flora began to turn around, as it were, and gradually re-inhabit recently glaciated ground. In this process, as the pollen evidence indicates (see the papers by Ogden), an arctic tundra-like vegetation, followed by a boreal one characterized by spruce and fir, were in all likelihood the first floras to occupy what is now Martha’s Vineyard. As the climate warmed further and the tundra and boreal vegetation became established further and further north and ultimately in the areas occupied today, vestiges of this floristic history were able to persist in suitable habitats on the Vineyard. By and large, however, other, more temperate and southern floras came to occupy Vineyard habitats and displace the earlier, northern floras. Primary among these were the vegetation of the southern coastal plain and the “continental” deciduous temperate forests that we know today. The fact that relic northern taxa have been able to persist in the Vineyard flora is, to my mind, because of habitats that remained available in the morainal hills that could support them.  While the outwash plain supports a few plants of northern affinities, most are found in up-island locales; by contrast, coastal plain floristic elements are found adjacent to the coast and down-island on the outwash plain.

In his analysis of the phytogeographic relationships of the flora of the Elizabeth Islands, Fogg divided the native taxa into three major groups – northern or boreal, southwestern or coastal plain elements, and continental or species of Canadian-Alleghanian affinity. The Vineyard flora can be divided into the same three groups using the same so-called “indicator species,” enumerated by Fogg. When this task is completed, it will be seen  that in reality, the northern or boreal group is poorly represented (5% of the indigenous flora), followed by a larger group (+ 20%) representing coastal plain/southwestern affinities, while the majority (+ 75%) represent the continental or Canadian-Alleghanian element. 

Fogg’s first impressions concerning the phytogeographical affinities of the Vineyard flora were mistaken. Given more complete knowledge of the Vineyard flora, it will be seen (and it comes as no surprise) that it falls into line very closely with the affinities determined by Fogg for the flora of the Elizabeth Islands.  In his study he found that about 9% represent boreal elements, 20% coastal plain taxa, and 70% illustrate continental or Canadian-Alleghanian relationships. Indicator species for both boreal and coastal plain affinities that help comprise the Vineyard flora are listed below. 

Vineyard Taxa Representative of the Northern or Boreal Flora

 

Lycopodium clavatum

Lycopodium obscurum

Rhus glabra cta

Angelica lucida

Ligustrum scothicum

Anaphalis margaritacea

Betula populifolia

Sagina procumbens

Hypericum boreale

Cornus canadensis

Drosera rotundifolia

Arctostapphylos uva-ursi

Chamaedaphne calyculata

Vaccinium macrocarpon

Lathyrus japonicus var. maritimus

Myriophyllum tenellum

Menyanthes trifoliata

Epilobium angustifolium

Epilobium palustre

Plantago maritima var. juncoides

Rumex maritimus var. fueginus

Ranunculus cymbalaria

Fragaria virginiana

Limosella australis

Carex canescens ssp. Disjuncta

Carex homathodes

Carex lanuginosa

Carex limosa

Carex silicea

Eleocharis uniglumis

Eriophorum tenellum

Rhynchocporus fusca

Eriocaulon aquaticum

Juncus articulates

Juncus militaris

Triglochin maritimum

Liparis loeselii

Agrostis stolonifera

Glyceria Canadensis

Glyceria obtuse

Puccinellia tenella ssp. Alascana

Spartina pectinate

Ruppia maritima

Vineyard Taxa Representative of the Southwestern Coastal Plain Flora (CP)

 

Lycopodiella inundata

Woodwardia virginica

Pteridium aquilinum var. pseudocaudatum

Thelypteris simulata

Chamaecyparis thyoides

Amaranthus pumilus

Hydrocotyle umbellata

Hydrocotyle verticillata

Ptilimnium capillaceum

Sanicula canadensis

Ilex glabra

Ilex opaca

Ascelpias verticillata

Aster subulatus

Baccharis halimifolia

Bidens connata

Coreopsis rosea

Eupatorium hyssopifolium

Eupatorium pilosum

Eurybia spectabilis

Euthamia tenuifolia

Gamochaeta purpurea

Hieracium gronovii

Krigia virginica

Lactuca hirsuta

Mikania scandens

Pityopsis falcata

Solidago latissimifolia

Solidago puberula

Symphyotrichum concolor

Symphyotrichum dumosum

Symphyotrichum tenuifolium

Onosmodium virginianum

Helianthemum bicknelii

Helianthemum canadense

Hudsonia ericoides

Lechea maritima

Lechea mucronata

Lechea pulchella

Clethra alnifolia

Triadenum virginicum           

Cuscuta compacta

Drosera filiformis

Drosera intermedia

Corema conradii

Leucothoe racemosa

Rhododendron viscosum

Chamaesyce polygonifolia

Chamaecrista fasciculata

Desmodium obtusum

Desmodium rotundifolium

Lespedeza angustifolia

Lespedeza capitata

Lespedeza procumbens

Lespedeza stuevei

Lespedeza virginicapica

Strophostyles helvula

Tephrosia virginiana

Quercus ilicifolia 

Quercus prinoides

Quercus stellata

Bartonia paniculata

Bartonia virginica

Sabatia stellaris

Myriophyllum pinnatum

Proserpinaca palustris

Lycopus amplectens

Teucrium canadense

Utricularia gibba

Utricularia subulata

Linum intercursum

Decodon verticillatus

Hibiscus moscheutos

Rhexia virginica

Nymphoides cordata

Comptonia peregrina

Myrica pensylvanica  Xyris difformis

Lugwigia alternifolia

Oenothera fruticose

Plantago virginica

Polygala cruciate

Polygala nuttallii

Polygonella articulate

Polygonum glaucum

Polygonum punctatum

Samolus valerandi

Aronia arbutifolia

Prunus maritima

Rosa palustris

Rubus pensilvanicus

Comandra umbellate

Agalinis maritima

Agalinis purpurea

Gatiola aurea

Lindernia dubia

Schwalbea americana

Boehmeria cylindrical

Viola x primulifolia

Viola sagittata

Sagittaria engelmanniana

Sagittaria teres

Arisaema triphyllum ssp. Stewardsonii

Peltandra virginica

Carex alata

Carex annectens

Carex bullata

Carex intumescens

Carex longii

Carex mitchelliana

Carex straminea

Cyperus filicinus

Cyperus grayi

Cyperus odoratus

Eleocharis rostellata

Fimbristylis autumnalis

Hemicarpha micrantha

Rhynchospora capitellata

Scirpus americanus

Scirpus cyperinus

Scirpus robustus

Scleria reticularis

Iris prismatica

Sisyrinchium angustifolium

Juncus effuses

Juncus subcaudatus

Lilium superbum

Calopogon tuberosus

Pogonia ophioglossoides

Tipularia discolor

Ammophila breviligulata

Andropogon virginicus

Aristida dichotoma

Aristida longispinus

Aristida purpurescens

Cenchrus longispinus

Dichanthelium commoonsianum

Dichanthelium commutatum

Dichanthelium dichotomum

Dichanthelium meridionale

Dichanthelium sphaerocarpon

Diplachne maritima

Panicum verrucosum

Paspalum setaceum var. psammophilum

Paspalum setaceum var. setaceum

Piptochaetium avenaceum

Schizachyrium scoparium

Setaria parviflora

Spartina alterniflora

Tridens flavus

Potamogeton oakesianus

Potamogeton pulcher

Smilax rotundifolia

Sparganium eurycarpum

Xyris difformi

 

The lists provided here, as noted above, are based on the investigations of John Fogg for the Elizabeth Island flora. There will undoubtedly be changes in the lists of indicator species and the percentages of each category within the total indigenous flora when an in-depth analysis of the Vineyard flora is undertaken at some future time.

It is nonetheless interesting to note that the Vineyard woodlands are comprised of species that for the most part fall into the continental or Continental-Alleghanian category. Included here are the majority of species that characterize up-island woodlands, viz. Quercus alba, Q. velutina, Sassafras albidum, Nyssa sylvatica, Acer rubrum, Ostrya virginiana, Carya alba, and Cornus florida. Only Ilex opaca, which is not uncommon in up-island woodlands, is of coastal plain affinities. By contrast, down-island woodlands include three other species of coastal plain affinities, viz. Quercus ilicifolia, Q. prinoides, and Q. stellata, which reaches its northern-most distribution in this region.

Pinus rigida and Juniperus virginiana, both signature trees of the Vineyard, are considered indicative of the continental floristic element. Yet Pinus rigida is the characteristic species of the New Jersey Pine Barrens on the coastal plain. From New Jersey southward, however, the pitch pine abandons the Coastal Plain and ranges inland in the Appalachian mountains southward through Virginia, the Carolinas, Kentucky and Tennessee to northern Georgia.  Juniperus virginiana, by contrast, is the most widely distributed coniferous tree in eastern North America (Burns & Honkala, 1990) and occurs in every state east of the 100th meridian. 

Before leaving the phytogeographical aspects of the Vineyard flora, it should be noted that Mehrhoff (1997) has suggested that many of the species that help comprise grassland vegetation have strong floristic affinities with the prairies of the Midwestern states. In Fogg’s classification these same species would fall into the “continental” category, yet Mehrhoff has suggested that the so-called “Prairie Province” itself extended eastward and dispersal of this flora (and fauna) directly onto the Coastal Plain was possible.  He hypothesizes that this possibility was most probable during a time when the climate was warmer and drier than currently during a so-called hypsithermal or xerothermic period, which occurred between 8,500 and 5,000 years before present.  It would have been at that time that such plants as Helianthemum canadensis, Viola fimbriata and V. pedata, Lespedeza capitata and L. hirta, Polygala polygama, Liatris scariosa var. novae-angliae,  Asclepias tuberosa, Schizachyrium scoparium and several others entered what is now New England from the west. As is the case for boreal and southern coastal plain plants, and if Mehrhoff’s theory is accepted, many of the Vineyard’s grassland taxa are remnants or relics that persist and reflect an earlier flora of some 5000 to 8,500 years ago.  As Fogg wrote concerning the flora of the Elizabeth Islands in 1930 (pp. 216, 217) “ In summing up, it need merely be pointed out that [the Vineyard], while serving, as does every other locality along the Atlantic coast, as a meeting ground for both northern and southern species of plants, exhibit[s] both qualitatively and quantitatively a very strong relationship with a widely dispersed flora of a continental nature, a fact which seems readily explicable upon the basis of the close connection existing between [the Island] and the inner, hilly part of Cape Cod, both as regards geologic history and general topography.”  To this I would add that the present flora of Martha’s Vineyard represents the current mix of species that reflect the presence of suitable habitats for their survival coupled with the history of successful dispersal (by whatever means) and establishment in the past.

Vegetation History

 John Brereton, the chronicler of Bartholomew Gosnold’s voyage of exploration and discovery in 1602, was the first to record impressions of the vegetation of Martha’s Vineyard. His observations in A Briefe and True Relation of the Discoverie of the North Part of Virginia (1602, reprinted 1903; see also D. B. & A. M. Quinn, eds., 1983) form the original observations on which speculations of the Vineyard vegetation prior to European settlement are based as well as discussions as to the changes in vegetation that have occurred since 1602.  Banks (1911) drew heavily on Brereton, and Ogden (1958) quoted appropriate passages.  These passages are presented again here to make them available to readers of this volume based on the rendition provided by Quinn & Quinn (1983).  Writing concerning the vegetation of the island, Brereton observed,

.  .  .  The chiefest trees of this Island, are Beeches and Cedars; the outward parts all overgrowen with lowe bushie trees, three or foure foot in height, which beare some kind of fruits, as appeared by their blossomes; Strawberries, red and white, as sweet and much bigger than ours in England: Rasberies, Gooseberies, Hurtleberies, and such an incredible store of Vines, aswell in the woddie part of the Island, where they run upon every tree, as on the outward parts, that we could not goe for treading upon them.

Summarizing the “commodities as we saw” in the Cape Cod region, Brereton recorded the following “Trees, Fruits, Plants and Herbs.”  

Sassafras trees, the roots whereof at 3.s the pound are 336.l the tunne. Cedars tall and straight, in great abundance. Cypres trees. Oakes. Walnut trees great store. Elmes. Beech. Hollie. Haslenut trees. Cherry trees. Cotton trees. Other fruit trees to us unknowen.  .   .   . Tobacco, excellent sweet and strong. Vines in more plenty that in France. Ground-nuts, good meat, & also medicinable. Strawberries. Raspeberries. Gooseberries. Hurtleberries. Pease growing naturally. Flaxe. Iris florentina, whereof apothecaries make sweet balles. Sorrell, and many other herbs wherewith they make sallets. 

As deduced by Ogden, the “Cedars” are undoubtedly Chamaecyparis thyoides, Atlantic white cedar, while the “cypres trees” are red cedar, Juniperus virginiana, and the so-called “Cotton trees” are probably a species of Populus.  The “Walnut trees” most likely refer to hickories (Carya spp.), inasmuch as walnuts (Juglans spp.) are not known on the Island, and as pointed out by Ogden, “walnut” was in 1602 a general term for both walnuts and hickories. Ground nuts are undoubtedly Apios americana, while hurtleberries are undoubtedly blueberries (Vaccinium spp.) and huckleberries (Gaylussacia spp.). The naturally growing “pease” or peas are likely native taxa of Lathyrus, while the citation of Iris florentina, not a native North American species, may  be to Iris versicolor or to  Acorus americanus, sweet flag, which was mistaken as an iris.  Based on Brereton’s observations (or the lack thereof) as well as early colonial construction records, it is evident that white pine (Pinus strobus L.), now a relatively common island tree, was not a component of the pre-colonial forests.

After Gosnold’s discovery of the Vineyard, settlement by Europeans brought European agricultural practices to the island as well as the settlers’ insatiable appetite for timber as a source of seemingly unlimited fuel and for construction. It also brought the first influx of Eurasian weeds, seeds of many of which undoubtedly came with domesticated animals as well as “impurities” in seed of European crop plants.  According to Ogden (1958), the pollen of common or dooryard plantain, also known as white man’s foot (Plantago major var. major), appears in the palynological record shortly after European settlement and ranks as one of the first weeds of European origin to enter the Vineyard flora. 

Despite the relatively small immigrant population, large areas of the Island were gradually cleared, in the first instance for subsistence agriculture, and secondly, for pastureland for grazing the settlers’ domestic animals, primarily sheep. Some timber was also used in construction (Ogden, 1958, 1961). As early as 1807 James Freeman was able to observe (1815, p. 12), “There is more grass land in Chilmark than in the other two [Edgartown and Tisbury] townships.” In reference to Edgartown and Tisbury, he wrote (p. 11), “More than one half of these two townships is covered with scrub oak and bitter oak, is of little or no value, and is not enclosed.” And while he claimed that the best land on the Island was in Gay Head, reserved for the Indians, he also observed that Gay Head (p. 51) “is destitute of trees.”  The general scene was summarized when he commented that (p. 14) “Very little wood land is left in Edgartown and Chilmark. . . . In Chilmark there is not half fewel enough of wood for the consumption of the inhabitants; and in Edgartown the greatest part of the fire wood which is used is brought from other places, chiefly from Buzzard’s Bay, Waquoit, and Coxit: the price of a cord is five or six dollars.” And in 1807 Freeman noted that (p. 14) “In the western part of the island, the land in general is fenced with stone walls,” and he also estimated that the number of sheep grazing the Vineyard was upwards of 20,000, and that goats had been commonplace in earlier years. He also reported (p. 15) that there were “. . . no deer, foxes, nor squirrels.” 

While Breiby (2004) presents evidence suggesting that some remnants of old-growth woodland still remains on the Island, and that these small tracks were probably never cut, it seems evident that most of the original up-island woodlands were cleared at one time or another. Foster and Motzkin (1999), however, present strong evidence in their study of the Manuel F. Correllus State Forest that even during the 19th century, when agricultural activity and its concomitant deforestation reached its peak, most of the Great Plain remained as oak and scrub woodland.  They present evidence that historically fire was common, and that during the 1800s cutting for firewood was probably the greatest disturbance in the area; very little of the area was cleared and plowed as cropland. Foster and Motzkin also provide evidence that the greatest disturbance of this area of the Island occurred during the 20th century with the establishment of plantations of coniferous trees.  

In any event, the historic and modern-day photographs presented by Dunwiddie (1994) also give clear evidence that a combination of intentional clearing and occasional fire undoubtedly helped to create a far more open, unwooded landscape on the Island than exists today. The old stone walls or “fences” that are today everywhere evident and help to define up-island Martha’s Vineyard also attest to widespread clearing. But during the last years of the nineteenth century and the initial decades of the twentieth century,  agriculture and sheep farming saw a steep decline, and the vegetation responded by gradually reclaiming and occupying the landscape. It may actually be correct to assert that Martha’s Vineyard is more heavily and completely wooded today than it has been since European settlement and historical records have been kept. And while it may be difficult to comprehend given the relatively short span of an individual life, the vegetation of Martha’s Vineyard is part of an ecosystem that is disturbance (including fire) dependent and subject to constant change.

Present-Day Plant Communities 

 

As mentioned in the introduction, the vegetation of a given region consists of the mosaic of plant communities that occupy the various habitats in the area and which are, in turn, influenced by both biotic and physical factors.  Given its variable topography and exposure to numerous physical factors (e.g., prevailing winds, salt spray, occasional hurricanes, edaphic conditions, precipitation or lack thereof, annual temperature fluctuations, and most importantly, occasional fire) and biotic factors (e.g., insects and diseases of various sorts, symbiotic soil relationships, grazing by deer, and competition for habitats and resources) the plants of the Vineyard have become distributed into those habitats that suit the ecological parameters of the individual species. Along with other species with similar or overlapping tolerances and requirements, the plants have formed natural communities over the Vineyard landscape.

As a result of a recent mapping effort, The Nature Conservancy (McCurdy, 2005) has made available four vegetation maps that cover the extent of Martha’s Vineyard and define the location of twenty vegetation types. The maps, which are available for viewing and downloading on the web, are simplified from more detailed, complex ones that identify over fifty plant community types for the Vineyard. For general use the 20 community types shown on the maps include the following categories as well as outlining the areas occupied by the airport and developed properties. These community types are: agricultural grasslands; coastal salt ponds; grasslands; heathlands, interdunal swales; maritime forests; maritime shrublands; mixed deciduous forests; mixed planted evergreens; oak woodland; open water (aquatic communities); pitch pine woodland; red cedar woodland; ruderal; shoreline; shrub oak; tidal flats; and wetlands.  These community types are described briefly below, while others, e.g., wetlands, are broken down into several types of communities in the following descriptions, which first appeared in The Flora of Martha’s Vineyard.

Community Descriptions

 

 The descriptions of community types that follow are taken, with permission, from the Flora of Martha’s Vineyard (Swanson & Knapp, 1999).

 

TERRESTRIAL COMMUNITIES

Dry Oak Forest  

This community has a more than 60% canopy cover of trees and typically occurs on well-drained soils of glacial outwash plains or moraines.  The dominant trees are white oak (Quercus alba), black oak (Q. velutina) or scarlet oak (Q. coccinea), with occasional pitch pine (Pinus rigida).  The shrub layer consists of low heath shrubs (i.e., Vaccinium spp., Gaylussacia baccata). The herbaceous layer consists of species such as bracken fern (Pteridium aquilinum), wintergreen (Gaulteria procumbens), trailing arbutus (Epigea repens), and Pennsylvania sedge (Carex pensylvanica). Example: Manuel F. Correllus State Forest.

Scrub Oak Barrens

This community, with a sparse canopy of trees (25 to 60% cover), occurs on well-drained, sandy soils of the moraine and outwash plain. The dominant shrub is shrub oak (Quercus ilicifolia) forming dense thickets, with occasional pitch pines (Pinus rigida). Below the scrub oak is a lower shrub layer composed of sweet fern (Comptonia peregrina), blueberries (Vaccinium angustifolium, V. pallidum) and huckleberry (Gaylussacia baccata).  Small patches of grassland within thickets are dominated by little bluestem (Schizachyytium scoparium). This community may be rich in species and is adapted to periodic fires. Example: Manuel F. Correllus State Forest.

Pine Barrens

This community has a sparse canopy of trees (25 to 60% cover) and also occurs on well-drained, sandy soils of glacial outwash plains or moraines, or thin, rocky soils of ridgetops. Pitch pine (Pinus rigida) is the dominant tree, with a shrub layer of heath plants such as huckleberry (Gaylusaccia baccata), blueberries (Vaccinium angustifolium, V. pallidum), sheep-laurel (Kalmia angustifolia) and sweet fern (Comptonia peregrina). Ground plants include wintergreen (Gaulteria procumbens), Canada mayflower (Maianthemum canadense), Pennsylvania sedge (Carex pensylvanica) and bracken fern (Pteridium aquilinum).  It is distinguished from scrub oak barrens by the dominance of heath shrubs rather than scrub oaks. Example: Caroline Tuthill Wildlife Reserve, Edgartown.

Coastal Heathlands

This dwarf shrubland community occurs on outwash plains and moraines of glaciated areas, near the ocean and within the influence of offshore winds and salt spray.  It is dominated by low heath or heath-like shrubs with greater than 50% cover. Characteristic shrubs include bearberry (Arctostaphylos uva-ursi), golden heather (Hudsonia ericoides), blueberry (Vaccinium angustifolium), huckleberry (Gaylusacia baccata), bayberry (Myrica pensylvanica) and beach plum (Prunus maritima). Characteristic species of grass/forbs include: little bluestem (Schizachyrium scoparium), Pennsylvania sedge (Carex pensylvanica), aster (Aster dumosum, A. linearifolius, A. solidagineus), bushy rockrose (Helianthemum dumosum) and northern blazing star (Liatris borealis). Example: Wasque Reservation, Chappaquiddick.

Sand Dune

A community dominated by grasses and low shrubs that occurs on active and stabilized dunes, with a mosaic of vegetation patches reflecting past disturbances. On stabilized dunes characteristic species include beach heather (Hudsonia tomentosa), bearberry (Arctostaphylos uva-ursi), beach grass (Ammophila breviligulata), cyperus (Cyperus spp.), seaside goldenrod (Solidago sempervirens), beach rose (Rosa rugosa), bayberry (Myrica pensylvanica), beach plum (Prunus maritima), poison ivy (Toxicodendron radicans), and lichens.  On active dunes beachgrass (Ammophila breviligulata), beach pea (Lathyrus maritimus var. glaber), seaside goldenrod (Solidago sempervirens), dusty miller (Artemisia stelleriana), sea rocket (Cakile edentula) and beach rose (Rosa rugosa) are characteristic. Example: East Beach, Cape Poge Wildlife Refuge, Chappaquiddick.

Sandplain Grassland

A globally rare community that occurs on excessively well-drained soils of outwash plains, and in fire-prone areas. It is dominated by grasses such as little bluestem (Schizachyrium scoparium), common hairgrass (Deschampsia flexuosa) and poverty grass (Danthonia spicata). Other characteristic species include Pennsylvania sedge (Carex pensylvanica), rush (Juncus greenei), golden aster (Chrysopsis falcata), bushy rockrose (Helianthemum dumosum), grass-leaved goldenrod (Euthamia graminifolia), gray and early goldenrods (Solidago nemoralis and S. juncea), bushy, white-topped, and stiff asters (Aster dumosus, A. paternus and A. linariifolius), racemed milkwort (Polygala polygama), bayberry (Myrica pensylvanica, northern dewberry (Rubus flagellaris), wild indigo (Baptisia tinctoria), Nantucket shadbush (Amelanchier nantucketensis), and bird’s-foot violet (Viola pedata).  Example: Katama Airfield, Edgartown.

Agricultural Grassland

This community includes agricultural land either planted in hay or field crops or maintained as a pasture area for livestock.  It is characterized by a dominance of introduced, weedy species of grasses and forbs such as sheep fescue (Festuca ovina), orchard grass (Dactylis glomerata), and cat’s ear (Hypochaeris radicata).  Example: Nat’s Farm, West Tisbury.

Maritime Shrubland

A shrubland community that occurs on dry seaside bluffs and headlands that are exposed to ocean winds and salt spray. It is dominated by a few characteristic species: beach plum (Prunus maritima), beach rose (Rosa rugosa), bayberry (Myrica pensylvanica), red cedar (Juniperus virginiana), winged sumac (Rhus copallina), poison ivy (Toxicodendron radicans), black cherry (Prunus serotina), highbush blueberry (Vaccinium corymbosum), and shadbush (Amelanchier canadensis). Example: Gay Head Cliffs Preserve.

Oak Savannah

This is a grass-savannah community that occurs on well-drained soils.  It is characterized by open-grown oaks (white oak, Quercus alba, and black oak, Q. velutina) with broad canopies, which are sparsely distributed amidst a grassy ground layer dominated by little bluestem (Schizachyrium scoparium) with forbs such as tick-trefoil (Desmodium ciliare), racemed milkwort (Polygala polygama), rockrose (Helianthemum dumosum and H. canadense), heath aster (Aster ericoides), and early goldenrod (Solidago juncea).  Shrubs are scattered through the community and may be locally dominant under large trees.  Example: Manuel Correllus State Forest, off Barnes Road.

Mesic Forest

This community, with a greater than 60% tree canopy cover, occurs on rich, moist, well-drained soils.  Among the dominant tree species are beech (Fagus grandifolia), red maple (Acer rubrum), black cherry (Prunus serotina), sassafras (Sassafras albidum), tupelo (Nyssa sylvatica), and white oak (Quercus alba).  The well-developed shrub layer includes arrowwood (Viburnum spp.), witch hazel (Hamamelis virginiana), winterberry (Ilex verticillata), shadbush (Amelanchier spp.) sweet pepperbush (Clethra alnifolia), and blueberry (Vaccinium pallidum and V. corymbosum).  The rich ground layer includes cinnamon fern (Osmuda cinnamomea), wood anemone (Anemone quinquefolia), wild geranium (Geranium maculatum), and wild sarsparilla (Aralia nudicaulis).  Examples: Menemsha Hills, Chilmark; Waskosim’s Rock Reservation, Chilmark/West Tisbury.

Maritime Red Cedar Forest

This community occurs on stabilized sand dune areas near the ocean. Red cedar (Juniperus virginiana) is the dominant tree, often forming nearly pure stands.  Also included are black oak (Quercus velutina) and bayberry (Myrica pensylvanica).  Characteristic ground layer plants are pinweed (Lechea spp.), poison ivy (Toxicodendron radicans), and lichens. Example: The Cedars, Cape Poge Wildlife Refuge, Chappaquiddick.

Ruderal Areas

This community occurs in area that receive frequent and heavy human disturbance, such as dumps, vacant lots, and roadsides. Dominant plants are often introduced, weedy species. Examples: Roadsides; landfills.

Landscape Areas

This community consists of residential and horticultural land maintained as yard or cultivated for the production of ornamentals. Weedy, introduced species often accompany cultivated ones. Example: home sites.

FRESHWATER WETLANDS

Shrub Swamp

An inland wetland dominated by shrubs that occurs along the shore of a pond or stream, in a wet depression or valley, or in areas with poor drainage.  The soil is usually rich in organics and peaty.  Characteristic shrubs are meadow-sweet (Spiraea alba var. latifolia), steeple-bush (Spiraea tomentosa), swamp azalea (Rhododendron viscosum), highbush blueberry (Vaccinium corymbosum), maleberry (Lyonia ligustrina), spicebush (Lindera benzoin), willows (Salix spp.), and arrowwood (Viburnum dentatum).  Example: Wintucket Cove, Edgartown.

Sphagnum Fen

A low-nutrient peatland that occurs on the coastal plain, in which the substrate is peat composed primarily of Sphagnum.  The dominant species are Sphagnum mosses, with scattered sedges, shrubs and stunted trees.  Characteristic herbs and shrubs include skunk cabbage (Symplocarpus foetidus), sundews (Drosera spp.), cranberry (Vaccinium macrocarpon), swamp candles (Lysimachia terrestris), rose pogonia (Pogonia ophioglossoides), grass pink (Calopogon tuberosus), marsh St. Johnswort (Triadenum virginicum), steeple-bush (Spiraea tomentosa), water willow (Decodon verticillatus), and sweet pepperbush (Clethra alnifolia). Scattered stunted trees such as red maple (Acer rubrum) may also be present.  Example: Cedar Tree Neck Sanctuary Bog, West Tisbury.

Forested Swamps (Including Seeps)

Occurs in poorly drained depressions.  Red maple (Acer rubrum) is usually the dominant tree, along with tupelo (Nyssa sylvatica) and sassafras (Sassafras albidum). The shrub layer is usually well developed and dense with spicebush (Lindera benzoin), winterberry (Ilex verticillata), chokeberry (Aronia spp.), arrowwood (Viburnum dentatum), sweet pepperbush (Clethra alnifolia), swamp azalea (Rhododendron viscosum) and highbush blueberry (Vaccinium corymbosum).  The herbaceous layer is characterized by cinnamon fern (Osmunda cinnamomea), sensitive fern (Onoclea sensibilis), skunk cabbage (Symplocarpus foetidus), sedges (Carex spp.), and spotted jewelweed (Impatiens capensis).  Example: Waskosim’s Rock Reservation, Chilmark/West Tisbury.

Wet Meadow

A community with rich, organic soils that are permanently saturated and seasonally flooded. They typically occur along streams near inlets and outlets of ponds.  The dominant species are sedges (Carex spp.), but also sensitive fern (Onoclea sensibilis), bunched broomsedge (Andropogon virginicus var. abbreviatus), bulrushes (Scirpus spp.), wild iris (Iris versicolor), steeplebush (Spiraea tomentosa), meadowsweet (Spiraea alba var. latifolia), smartweeds (Polygonum spp.), boneset (Eupatorium spp.) and meadow-rue (Thalictrum pubescens).  Example: Ox Pond Meadow, Edgartown.

Fresh Water Marsh

A community that occurs in rich, organic soils that are permanently saturated, water levels seasonally fluctuate, and flowing water is often present. Characteristic vegetation includes mannagrass (Glyceria canadensis), tussock sedge (Carex stricta), wool grass (Scirpus cyperinus), wild iris (Iris versicolor), and cattails (Typha spp.).  These areas that have been disturbed may be dominated by reedgrass (Phragmites australis) and purple loosestrife (Lythrum salicaria).  Example: Wompesket Preserve, Tisbury.

Coastal Plain Pond Shore

The gently sloping shore of a coastal plain pond with seasonally and annually fluctuating water levels.  The substrate is sandy, gravelly or mucky.  Species composition varies from year to year dpending on water levels.  In wet years vegetation is sparse with only a few emergents and aquatics present. In dry years a dense growth of herbaceous species may be present.  Characteristic species include Atlantic prickly sedge (Carex atlantica ssp. atlantica), rushes (Juncus spp.), panic grasses (Panicum spp.), St. Johnsworts (Hypericum spp.), northern meadow-beauty (Rhexia virginica), golden hedge-hyssop (Gratiola aurea), lance-leaved violet (Viola lanceolata), and yellow-eyed grass (Xyris spp.).  Example: Ripley’s Field Preserve, Tisbury.

Interdunal Swale

A mosaic of wetlands that occur in low areas between dunes with soil surfaces at groundwater level.  Soils are either sand or peaty sand; water levels fluctuate seasonally and annually. The dominant species are sedges and herbs; low shrubs are usually present, but not dominant.  Characteristic species are flatsedge (Cyperus spp.), marsh rush (Juncus canadensis) blue flag (Iris versicolor), sundews (Drosera spp.), cranberry (Vaccinium macrocarpon), yellow-eyed grass (Xyris difformis), bayberry (Myrica pensylvanica), and highbush blueberry (Vaccinium corymbosum).  Example:  Along Moshup’s Trail, Aquinnah. 

SALT/BRACKISH WATER WETLANDS

Coastal Salt Pond Shores

A saline to brackish community along the shores of salt ponds that regularly open to the sea.  Salinity and water levels fluctuate throughout the year.  Characteristic species that occur along the shore are cordgrass (Spartina alterniflora), salt-meadow grass (Spartina patens), fresh-water cordgrass (Spartina pectinata), pennyworts (Hydrocotyle spp.), seabeach orach (Atriplex arenaria), knotweeds (Polygonum spp.), seaside goldenrod (Solidago sempervirens), and saltmarsh fleabane (Pluchea odorata var. succulenta).  Example: Sepiessa Point Reservation, Long Point Wildlife Refuge, West Tisbury.

Salt Marsh

A coastal marsh community that occurs in sheltered areas of the seacoast.  The dominant species are salt-meadow grass (Spartina patens), cordgrass (Spartina alternifolia), and spikegrass (Distichlis spicata).  Other characteristic species are black-grass (Juncus gerardi), switchgrass (Panicum virgatum), seabeach orach (Atriplex arenaris), sea-lavender (Limonium carolinianum), slender saltmarsh aster (Aster tenuifolius), seabeach goldenrod (Solidago sempervirens), groundsel tree (Baccharis europaea), and sea blite (Suaeda maritima).  Example: Basin Road, Menemsha.

Brackish Cove Shores

A brackish marsh community that occurs in sheltered areas of the seacoast at the upper margins of salt ponds. Characteristic species include freshwater cordgrass (Spatina pectinata), saltmeadow grass (Spartina patens), softstem bullsedge (Scirpus validus), saltmarsh threesquare (Scirpus americanus), and saltpond pennywort (Hydrocotyle verticillata).  Example: Long Point Wildlife Refuge, West Tisbury.

Coastal Beaches

A sparsely vegetated community that occurs on unstable sandy shores above mean high tide. Characteristic species include beachgrass (Ammophila breviligulata), sea-rocket (Cakile edentula), halberd-leaved orach (Atriplex hastata), seabeach orach (Atriplex arenaria), seabeach sandwort (Honkenya peploides), seabeach saltwort (Salsola kali), seabeach knotweed (Polygonum glaucum), and seaside goldenrod (Solidago sempervirens).  Example: Norton Point Beach, Edgartown.

AQUATIC COMMUNITIES

Coastal Plain Ponds

The aquatic community of the permanently flooded portion of a coastal plain pond with seasonally and annually fluctuating water levels.  These shallow, groundwater-fed ponds occur in kettle-holes or shallow depressions in the outwash plain.  Aquatic vegetation may be abundant.  Characteristic species include water-shield (Brasenia schreberi), white water-lily (Nymphea odorata), spikerush (Eleocharis spp.), bladderwoort (Utricularia spp.), and pondweed (Potamogeton spp.).  Example: Seth’s Pond, West Tisbury.

Coastal Plain Streams

The aquatic community of slow-moving, often darkly-stained streams of the coastal plain.  Often there is abundant submerged vegetation.  Characteristic species are pondweeds (Potamogeton spp.), bladderwort (Utricularia spp.), and duckweed (Lemna minor).  Little fieldwork has been done on this community type on the Island.  Example: Mill Brook, Waskosim’s Rock Reservation, Chilmark/West Tisbury.

Coastal Salt Ponds

An aquatic community inhabiting ponds formed by barrier beaches closing off a bay.  The water is brackish or slightly brackish, occasionally becoming saline when the barrier beach is opened or breached by storms.  Characteristic species are eelgrass (Zostera maritima), pondweeds (Potamogeton spp.), and widgeon grass (Ruppia maritima).  Examples: Edgartown and Tisbury Great Ponds.