Physiognomy and Structure: This vegetation is variable in structure, ranging from sparsely distributed grasses on foredunes, sometimes intermixed with low deciduous shrubs, to dwarf-shrublands of interdunes and low shrublands of coastal sandplains.

Floristics: Morella pensylvanica, Ammophila breviligulata, and Hudsonia tomentosa are species that distinguish this group from vegetation in similar habitats farther south. The foredune areas tend to be low in plant species richness but have a characteristic set of forbs and occasional low shrubs associated with them. Backdune areas may be dominated by a variety of herbs and sometimes have fairly high species richness. Characteristic species (in different associations within the group) include Ammophila breviligulata, Andropogon virginicus, Cenchrus tribuloides, Diodia teres, Hudsonia tomentosa, Morella pensylvanica, Panicum amarum, Panicum virgatum, Polygonella articulata, Schizachyrium littorale, Schizachyrium scoparium, and Solidago sempervirens, among others. Schoenoplectus pungens sometimes occurs in overwash areas where sand has buried interdunal wetlands. Heathland and sandplain grassland settings are characterized by Amelanchier nantucketensis, Arctostaphylos uva-ursi, Carex pensylvanica, Corema conradii, Deschampsia flexuosa, Gaylussacia baccata, Hudsonia ericoides, Hudsonia tomentosa, Schizachyrium scoparium, and Vaccinium angustifolium. They provide habitat for several rare or uncommon forbs, including Liatris scariosa var. novae-angliae and Agalinis acuta.

Dynamics:  The environment of this group is one of the most dynamic in existence for terrestrial vegetation. Reworking of sand by storms or by slower eolian processes may completely change the local environment in a short time, altering the substrate that effectively removes existing vegetation and provides new habitat for establishment of different vegetation. Some plants, such as Ammophila breviligulata and Hudsonia tomentosa, are well-adapted to sand burial and can send new shoots above the sand surface. Many of these sites are fairly early in the process of primary succession on recent surfaces. Chronic salt spray is an ongoing stress. Overwash and extreme salt spray from storms are frequent disturbances. Vegetation interacts strongly with geologic processes; the presence of grass is an important factor in the development of new dunes. Alteration of dynamic processes, such as artificial enhancement of dunes by planting or sand fencing, can have drastic effects on this vegetation, causing large areas to succeed to woody dominance. Limited areas along the New York and New England coastline support maritime sandplains, where sand movement is more limited but exposure to the elements is still high. The sandplain grasslands and heathlands that develop in these habitats have been affected by a combination of exposure, fire, and land use. Prior to European settlement, these habitats are believed to have occurred in limited areas near the coast, where the effects of wind and salt spray prevented tree growth; there may also have been patches in the vicinity of Native American settlements, based on the prevalence of charcoal in some palynological cores. Some heathlands may have developed on severely disturbed soils following the abandonment of agriculture and grazing.