Seabeach Amaranth Making a Comeback

For the past 10 years, the threatened seabeach amaranth has been making a comeback, reappearing on east coast shorelines from Massachusetts to South Carolina.

Looking much like a weed you might pull out of a garden, the seabeach amaranth, Amaranthus pumilus Raf.--sometimes referred to as seabeach pigweed--is currently on the federal roster of threatened species. It grows where other plants won’t and tends to disappear if other plants move in on it.

Far away from the eastern beaches, samples of A. pumilus are being conserved as part of a comprehensive collection of amaranth germplasm maintained in the U.S. Department of Agriculture’s National Plant Germplasm System.

The amaranth collection, located at the North Central Regional Plant Introduction Station (NCRPIS) in Ames, Iowa, comprises about 3,500 accessions. The entire germplasm collection at Ames comprises 47,000 accessions with more than 340 genera representing 1,900 species. It includes cultivated grain and vegetable types, ornamental and wild species from many parts of the world. The North Central Regional Plant Introduction Station is operated by USDA’s Agricultural Research Service.

David M. Brenner, curator of the Amaranthus germplasm at NCRPIS, collected six distinct populations with large seed samples representing many individual plants on ocean beaches along the North and South Carolina coastlines. Then, he tested the seeds to develop methods to regenerate the species. By keeping the seeds for three months in cool, moist surroundings, Brenner obtained about 90 percent synchronized germination.

The seabeach amaranth is of special interest to agriculture because it has atypically large seeds for the genus and could perhaps be the source of crop-improving genes for cultivated amaranths. Consumers in many countries enjoy amaranths as both a leafy vegetable and as a “pseudo” cereal. They are an extremely good source of bioavailable iron--more so than spinach--and have a rare, high-quality plant protein that can be used to enrich grain products. Approximately 1,000-5,000 acres of amaranths are grown annually in the United States for grain that is incorporated into health foods.

ARS is the chief scientific research agency of the U.S. Department of Agriculture.