Annuals. Stems erect, 1–3 dm. Cauline leaves: blade ovate to spatulate, margins crenate, dentate, or sinuate (not pinnatifid). Racemes usually 1–2 dm, rarely longer; rachis not geniculate. Fruiting pedicels 2.5–7 mm. Flowers: sepals ca. 4 mm, lateral pair not saccate basally; petals white or lavender, 5.3–8 × 1.3–2.6 mm, claw distinct. Fruits (terete or 4-angled), lanceoloid, 14–22 × 3–4 mm, (constricted at articulation of segments); proximal segment terete, long-cylindrical, (5–8.5 mm); terminal segment fusiform, (9–15 mm, beak conic), apex acute. Seeds: cotyledons accumbent. 2n = 18.
Phenology: Flowering spring–fall.
Habitat: Sandy shores
Elevation: ca. 0 m
Fla., La., Tex.
Cakile constricta is disjunct in Florida (not known from the Keys or southwestern Florida, where immature plants of C. lanceolata subspp. fusiformis and pseudoconstricta may be confused with it).