-3- 



of my Master's Thesis (McDonnell, 1979), I have documented 

 the flora of Plum Island based on field studies, herbarium 

 specimens, and literature sources. It is hoped that this 

 flora will provide a stimulus, as well as a basis, for 

 future study. Information concerning corrections or 

 additions to the flora will be greatly appreciated by the 

 author . 



PHYSICAL FEATURES 



Plum Island covers approximately 3,644 acres (1,475 

 ha). It varies in width from one quarter (0.4 km) to three 

 quarters of a mile (1.2 km) (Fig. 2). The upland areas 

 cover some 1,680 acres (680 ha) including Cross Farm Hill, 

 Stage Island, Bar Head, and the dunes. The freshwater 

 habitats on the island cover approximately 375 acres (152 

 ha). Most of which are included in North, South, and Stage 

 Island Pools, all of which are artifical impoundments 

 created by Parker River National Wildlife Refuge personnel 

 (PRNWR records). There are a few small seasonal pools, wet 

 pans, and swamps scattered throughout the dunes as well as 

 on Stage Island and Cross Farm Hill, but many of these were 

 also artificialy created. Salt marsh fringes the western 

 edge of the island and covers approximately 1,500 acres (600 

 ha) . This is only a small portion of the entire salt marsh 

 system which occurs behind the island. Shaler (1885) states 

 from his survey of the marshes of the Eastern United States 

 that this is the largest salt marsh system north of Long 

 Island Sound, comprising over 20,000 acres (8,000 ha). 



Some 2,900 acres (1,180 ha), the southern two-thirds of 

 the island, are now included in the Parker River National 

 Wildlife Refuge. In addition, 120 acres (50 ha) at the 

 southern tip of the island have been set aside as a State 

 Park of the Commonwealth of Massachusetts. Combined, this 

 acreage makes up one of the largest semi-natural barrier 

 beach dune systems north of Cape Cod. 



The relatively undisturbed southern portion of the 

 island exhibits the classical physiographic features of a 

 barrier beach dune system. Figure 3 illustrates the typical 

 physiographic features and the major vegetation zones 

 encountered on an east to west transect across the island. 

 The eastern edge of the island, bordering the ocean, is 

 fringed by a strip of beach which changes morphologically 

 depending on the season (Abele, 1977) . Parallel to the 

 beach, and adjacent to it, is a foredune ridge which varies 

 from 5 feet (1.6 m) to 35 feet (11.6 m) in height. This 

 ridge receives the greatest impact from storms and is 



