Frankenia comprises about 70–80 species of shrubs, subshrubs and herbaceous plants. Frankenia has a widespread but patchy distribution throughout temperate and subtropical areas of the world, being absent from the tropics. They have opposite, simple leaves, generally small and somewhat heather-like, and often with salt-excreting glands in sunken pits. Their flowers are small, either solitary or borne in various kinds of cyme. Each flower has four to seven sepals, joined at the base into a tube, and four to seven overlapping petals, narrowed at the base. The stamens are often arranged in two whorls of three each. The ovary is made up of one to four carpels (usually three). The fruit is a capsule, enclosed in the persistent sepals. The seeds have a central embryo with considerable starchy endosperm on each side.