Their laterally flattened bodies are an adaptation to life in wet reedbeds and marshes, enabling them to slip easily through the dense semi-aquatic vegetation.

Typically these birds have streaked brown upperparts, blue-grey on the face or breast, and barred flanks.

[2] Three endemic South American species are endangered by habitat loss, and the Madagascar rail is becoming rare.

The genus Rallus was erected in 1758 by the Swedish naturalist Carl Linnaeus in the tenth edition of his Systema Naturae.

[7] The genus contains 14 extant species:[8] "R." sumiderensis apparently refers to prehistoric remains of the Zapata rail (Cyanolimnas cerverai).