The northern seashore species of Atriplex are annuals with leaves with a distinct petiole and a linear, oblong, triangular or hastate blade (and every shape between these). The leaves are opposite at the base of the stem, alternate upwards. Leaves and inflorescences are usually more or less pubescent with globular hairs (‘mealy’) characteristic of parts if their family, Amaranthaceae. Flowers are concentrated as clusters in leafy panicles, unisexual but together in clusters on the same plant. Male flowers have 5 tepals. Female flowers are without perianth but are enclosed inside two bracteoles, increasing much in size after flowering and during fruit maturation. The pollination is assumed to be mainly by wind but neighbour pollination within the inflorescences is a distinct possibility. The fruit (a nut) is dispersed by sea currents enclosed by the bracteoles serving as floating tissue (Elven 1984). The plant on Bjørnøya must have germinated from a fruit dispersed by sea currents, probably from N Fennoscandia or N European Russia.
The genus is easily recognized even in young, non-flowering plants, but the species are not easily recognized before fruiting stage. The seashore species of Atriplex are notoriously difficult to identify unless they have fully grown bracteoles. Five species co-occur on the seashores of N Fennoscandia (including the Murman Coast on the Russian Kola Peninsula), see Elven (1984): A. littoralis L. north to Troms, A. glabriuscula Edmondston along the entire coast, A. prostrata Boucher ex DC. (ssp. latifolia (Wahlenb.) Rauschert) more or less along the entire coast, A. praecox Hülph all along the coast, and A. lapponica Pojark. in Finnmark, on the Murman coast and by the White Sea. The leaf shape of the Bjørnøya material excludes A. littoralis and A. lapponica but the three others are all candidates. The least hardy of these is A. prostrata. We do not know why Gustafsson (2001) assigned the Bjørnøya plant to just A. prostrata but we here follow his assignment.