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A leafy green plant with purple and red coloring around the edges of leaves and stems growing in the sand.
Information icon Seabeach amaranth in North Carolina. Photo by Dale Suiter USFWS

Seabeach amaranth

Amaranthus pumilus

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.

Appearance

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.

A leafy green plant with purple and red coloring around the edges of leaves and stems with tiny yellow flowers growing in the sand.
Flowering seabeach amaranth. Photo by USFWS.

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.

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 arenot 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.

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.

Conservation challenges

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.

Two biologists take a close look at a plant growing in the sand.
Dale Suiter, Endangered Species Biologist shared his knowledge about the threatened Seabeach Amaranth (Amaranthus pumilus) with fellow biologist, Ann Marie Lauritsen. Photo by Lilibeth Serrano, USFWS.

Natural disasters such as tropical storms and nor’easters can inundate or wash away plants before they set seeds.

Recovery plan

The Seabeach amaranth recovery plan was completed in 1996, download the plan.

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 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.

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.

Subject matter experts

Designated critical habitat

Critical habitat has not been designated for this species.

Federal register notices

The following Federal Register documents were automatically gathered by searching the Federal Register Official API with this species’ scientific name ordered by relevance. You can conduct your own search on the Federal Register website.

  • We're sorry but an error occurred. Visit the Federal Register to conduct your own search.

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