Herbs, subshrubs, or shrubs, perennial or, rarely, annual. Stems rounded to noticeably angled. Leaves opposite, simple, petiolate or sessile, with salt glands, estipulate, paired leaves connate basally by membranous, sheathing margins with stiff, white hairs, flattened and appressed to stem; petiole narrow to broad, fleshy to flattened and chartaceous; blade margins entire. Inflorescences solitary flowers or terminal or axillary, simple or compound dichasia (frequently with some monochasial branching), bracteate; bracts 4, basally connate (rarely incompletely connate). Flowers bisexual [unisexual]; sepals 4–6[–7], persistent, connate, ribbed; petals 4–6[–7], distinct, clawed basally, limb spreading, scalelike appendage or ligule embryo straight; endosperm present.
United States, Mexico, South America, Eurasia, Africa, Atlantic Islands, Australia, introduced in West Indies.
Genus 1, species ca. 70 (5 in the flora).
Kubitzki (2003b) recognized two genera, Frankenia and Hypericopsis, in Frankeniaceae; molecular evidence supports inclusion of Hypericopsis within Frankenia (J. F. Gaskin et al. 2004). Molecular studies have placed Frankeniaceae and Tamaricaceae, which generally have been recognized as related families, in the Caryophyllales (for example, P. Cuénoud et al. 2002).