Annual.

See Comments. Only 2 leaves on the single plant found in Svalbard.

See Comments. Not found flowering in Svalbard.

See Comments. Not found flowering in Svalbard.

Not found fruiting in Svalbard.

Sexual reproduction by seeds. Not found fruiting in Svalbard.

Nothing similar in the Svalbard flora.

Sandy and gravelly seashores.

Native but ephemeral. This is a North Atlantic endemic found once on Spitsbergen (see Comments). The species is not part of the stable flora of Svalbard.

Otherwise distributed in Iceland, the Faeroes, Scandinavia, and NW European Russia.

Cakile maritima ssp. islandica is an annual seashore plant found once in Svalbard, as a juvenile plant with two leaves on the shore at Deltaneset at Isfjorden (Nordenskiöld Land), 21. Aug. 1939, leg. A. Egge & E. Hadač. The find is described in detail by Hadač (1944) who stated that the distance to the nearest known locality, on the European mainland, is ca. 1000 km. When fully developed, this plant is a succulent herb with alternating, petiolate and deeply lobed leaves, large, pink flowers with 4 petals in a short raceme, and an articulated siliqua with two joints, each with one seed. The siliqua has a long and beaked stylar part (the upper joint) and is constricted between the joints, without beaks protruding at the base of the upper joint (such beaks present in the three other Nordic subspecies). These fruits (or half fruits) can float for long periods in sea water without loss of their germination ability (Rodman 1974; Elven & Gjelsås 1981). The plant in Svalbard must have germinated from a fruit dispersed by sea currents from N Fennoscandia or Russia to Svalbard and far into Isfjorden.

Cakile maritima is a polymorphic species with four accepted subspecies in N Europe: ssp. maritima along the west coasts of Europe from Portugal to Nordland and Troms in N Norway; ssp. baltica (Jord. ex Rouy & Foucaud) Hyl. ex P.W.Ball along the coasts of the Baltic and the Skagerrak; ssp. integrifolia (Hornem.) Hyl. ex Greuter & Burdet on sandy coasts in sand dune systems from France north to S Norway; and ssp. islandica in Iceland, the Faeroes, N Norway, and the Murman and White Sea areas in Russia. The diagnostic characters distinguishing the subspecies are found in the shape of the leaves and of the fruits. The leaf characters make it possible to say, with a fair certainty, that the plant found on Spitsbergen belongs to ssp. islandica.

Elven, R. & Gjelsås, T. 1981. Strandreddik (Cakile Mill.) i Norge. — Blyttia 39: 87—106.

Hadač, E. 1944. Die Gefässpflanzen des "Sassengebietes" Vestspitsbergen. — Norges Svalbard- og Ishavsundersøkelser 87. 73 pp. + XIV Tafel.

Rodman, J.E. 1974. Systematics and evolution of the genus Cakile (Cruciferae). — Contributions of the Gray Herbarium 205: 3—146.