The number of species is disputed, with some authorities only accepting a single species, while others accept up to five species. The following species are accepted by the Med-Checklist:
When treated as a monospecific genus, all are included within E. vesicaria.
They are annual plants growing to 20–100 cm tall. The leaves are deeply pinnately lobed with four to ten small lateral lobes and a large terminal lobe. The flowers are 2–4 cm diameter, arranged in a corymb, with the typical Brassicaceae flower structure; the petals are creamy white with purple veins, and the stamens yellow. The fruit is a siliqua (pod) 12–25 mm long with an apical beak, and containing several seeds.