Its type species, Prockia crucis, is highly polymorphic and has a broad distribution, from Mexico and the West Indies to Uruguay and northern Argentina.

[2] Historically, Prockia was characterized by having pseudo-axile placentation (i.e., parietal placentae that intrude into the center of the ovary and eventually fuse, appearing axile) and 3-merous flowers and lacking nectaries.

[3] However, discoveries of new species have confounded a simple morphological diagnosis of the genus, as P. pentamera has 5-merous flowers, and P. oaxacana and P. krusei are polygamodioecious or androdioecious and have more typical parietal placentation.

[4] Formerly placed in the heterogeneous family Flacourtiaceae,[5] Prockia is now classified in tribe Prockieae of Salicaceae, along with close relatives Banara, Hasseltiopsis, Pineda, and Neosprucea.

[6] Prockia crucis is sometimes confused with Pineda ovata (Salicaceae) in the high elevations of Bolivia.