Utricle scarcely compressed, irregularly ruptured below by the developing seed, the rounded apex considerably pilose, gibbous to one side of the style with a short horn-like process.
Ovary scarcely compressed, uniovulate, considerably pilose above and corniculate to one side at the apex; style slender, stigma simple, capitate.
Stamens 5; filaments delicate, fused below with very short and blunt pseudostaminodes between; anthers bilocular.
Perianth segments 5, narrow, 3-nerved, mucronate, only a narrow central section coloured.
Leaves entire, opposite on simple or branched stems.
Erect annual herbs.
Endosperm copious.