FWS Focus

Overview

Characteristics
Overview

Taxon: Plant 

Range: South CarolinaNorth CarolinaVirginiaMarylandNew JerseyNew YorkRhode Island (historic) and Massachusetts (recently reintroduced). 

Status: Threatened; listed April 7, 1993 

Seabeach amaranth is an annual plant found along Atlantic Coast barrier beaches. Originally known from Massachusetts to South Carolina, it has not been observed north of Long Island, New York, in many years until a reintroduction to Nantucket Island and Monomoy National Wildlife Refuge on Cape Cod, Massachusetts in 2017. Based on a rangewide decline of the species, it was listed as threatened on April 7, 1993. 

Partnerships, research and projects 

The U.S. Fish and Wildlife Service works with a variety of local, state and federal land managers to protect and monitor seabeach amaranth populations throughout the range of the species. Researchers at East Carolina University, North Carolina Botanical Garden, North Carolina State University, Raritan Valley Community College, University of North Carolina at Wilmington and Columbia University have conducted demographic and habitat research projects since the species was listed as threatened in 1993. 

Recently, the Service, in cooperation with the North Carolina Botanical Garden initiated a Cooperative Recovery Initiative project that involved planting seabeach amaranth on or near six national wildlife refuge national wildlife refuge
A national wildlife refuge is typically a contiguous area of land and water managed by the U.S. Fish and Wildlife Service  for the conservation and, where appropriate, restoration of fish, wildlife and plant resources and their habitats for the benefit of present and future generations of Americans.

Learn more about national wildlife refuge
throughout the historical range of the species. Approximately 2,000 seabeach amaranth seeds were planted at each refuge during May and June of 2017. Biologists and interns monitored the plots for germination, flowering and fruiting throughout the 2017 growing season and plan to conduct surveys for new seabeach amaranth plants growing in the vicinity of those plots from 2018 to 2020. 

Threats to the species include coastal development, sea level rise, beach stabilization structures and recreation such as beach driving and pedestrian traffic. Herbivory by native and non-native species (such as webworms, white-tailed deer, sika deer and feral horses) may harm seabeach amaranth plants. Natural disasters such as tropical storms and nor’easters can inundate or wash away plants before they set seeds. 

How you can help 

Avoid stepping on or driving over beach and dune vegetation. Avoid walking in areas specifically roped or fenced off for wildlife as seabeach amaranth often occurs in areas where Piping plovers and other shorebirds nest. 

Please report locations of seabeach amaranth to the Service’s lead recovery biologist, Dale_Suiter@fws.gov, and the appropriate state natural heritage program. 

 

U.S. Fish and Wildlife Service. 1996. Recovery Plan for Seabeach Amaranth (Amaranthuspumilius) Rafinesque. Atlanta, Georgia

Scientific Name

Amaranthus pumilus
Common Name
seaside amaranth
Seabeach amaranth
FWS Category
Flowering Plants
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Habitat

Characteristics
Habitat

Seabeach amaranth occurs on barrier beaches, where its primary habitat consists of overwash flats at the ends of islands that are accumulating more sand and lower developing dunes and upper strands of non-eroding beaches. It occasionally establishes small temporary populations in other habitats, including sound-side beaches, overwash areas in developing dunes, and sand and shell material placed as beach replenishment or dredge spoil. Seabeach amaranth appears to be intolerant of competition and does not occur on well-vegetated sites. The species appears to need extensive areas of barrier island beaches and inlets that are not stabilized by perennial vegetation. These characteristics allow it to move around in the landscape as a fugitive species, occupying suitable habitat as it becomes available. The species is an effective sand binder, building small dunes where it grows. 

U.S. Fish and Wildlife Service. 1996. Recovery Plan for Seabeach Amaranth (Amaranthuspumilius) Rafinesque. Atlanta, Georgia

Coastal

The land near a shore.

Characteristic category

Similar Species

Characteristics
Similar Species

Seaside spurge (Chamaesyce polygonifolia) is a close vegetative associate of seabeach amaranth. These two species share a low growth form and reddish stems. However, the leaves of seaside spurge are lighter green, more elongated, and less shiny than seabeach amaranth. 

Characteristic category

Lifecycle

Characteristics
Lifecycle

Upon germinating, seabeach amaranth initially forms a small reddish, upright spring. Soon the seedling begins to branch into a low-growing rosette consisting of 5 to 20 branches and typically reaching 4 to 12 inches in diameter. Occasionally a plant may reach a yard or more across, with a hundred or more branches. The stems are fleshy and pink-red or reddish, with small rounded leaves. Clustered toward the tip of the stem, the leaves are somewhat shiny, spinach-green in color, and have a small notch at the tip. Small white flowers and dark seeds are located in inconspicuous clusters along the stems. As they age throughout the fall, plants often turn reddish or purplish, and some stems and leaves may die back.

Seabeach amaranth germination takes place over a relatively long period, beginning as early as April in the south and starting in mid-May or early June farther north. Germination continues at least through July. Flowering begins as soon as plants have reached sufficient size, sometimes as early as June in the Carolinas but more typically commencing in July. Flowering continues until the plant dies in late fall or early winter. Seed production begins in July or August and reaches a peak in most years in September; seeding likewise continues until the plant dies. Seabeach amaranth plants that are not lost to burial or flooding from fall storms may persist through November in the north, and into January farther south. 

U.S. Fish and Wildlife Service. 1996. Recovery Plan for Seabeach Amaranth (Amaranthuspumilius) Rafinesque. Atlanta, Georgia

Reproduction

Flowering begins as soon as plants have reached sufficient size, sometimes as early as June, but more typically in July, and continuing until the death of the plant in late fall. Seed production begins in July or August and peaks in September during most years, but continues until the death of the plant. Weather, including rainfall, hurricanes, and temperature extremes, and predation by webworms and deer have strong effects on the length of the reproductive season for this species. As a result of one or more of these influences, the flowering and fruiting period can be terminated as early as June or July. Under favorable circumstances, however, the reproductive season may extend into late fall.

Strand, A. 2005. Seabeach Amaranth 2004 census and seed rain estimates. College of Charleston, Charleston, South Carolina. 21 pp. 

U.S. Fish and Wildlife Service. 1996. Recovery Plan for Seabeach Amaranth (Amaranthuspumilius) Rafinesque. Atlanta, Georgia

Lifespan

The maximum lifespan of a seabeach amaranth plant is about 8 months, though many plants do not persist that long. This species overwinters as seeds, which are believed to be capable of persisting in the beach environment for many years until suitable conditions for gemmation are present.  

U.S. Fish and Wildlife Service. 1996. Recovery Plan for Seabeach Amaranth (Amaranthuspumilius) Rafinesque. Atlanta, Georgia

Characteristic category

Physical Characteristics

Characteristics
Size & Shape

Seabeach amaranth has stems that are fleshy and pinkish-red or red, with small rounded leaves that are 0.5 – 1 inch (in) (1.3 - 2.5 centimeters; cm) in diameter. The leaves, with indented veins, are clustered toward the tip of the stem and have a small notch at the rounded tip. Flowers and fruits are relatively inconspicuous, borne in clusters along the stems. Germination occurs over a relatively long period of time, generally from April to July. Upon germination, the species forms a small unbranched sprig, but soon begins to branch profusely into a clump. This clump often reaches 30 cm in diameter and consists of five to 20 branches. Occasionally, a plant may grow as large as a meter or more across.

U.S. Fish and Wildlife Service. 1996. Recovery Plan for Seabeach Amaranth (Amaranthuspumilius) Rafinesque. Atlanta, Georgia

Geography

Characteristics
Range

Historical range

Historically, seabeach amaranth occurred in nine states along the northeast and mid-Atlantic coast from Massachusetts to South Carolina (excluding Connecticut).

Current range

Natural populations of seabeach amaranth currently occur in New York, New Jersey, Delaware, Maryland, Virginia, North Carolina, and South Carolina. Seabeach amaranth was recently planted on Nantucket Island and at Monomoy National Wildlife Refuge, both in Massachusetts.

U.S. Fish and Wildlife Service. 1996. Recovery Plan for Seabeach Amaranth (Amaranthuspumilius) Rafinesque. Atlanta, Georgia

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