Casuarina pauper, commonly known as black oak, belah or kariku,[2] is a species of flowering plant in the family Casuarinaceae and is endemic to southern continental Australia.

The female cones are covered with rusty hairs, on a peduncle 1–14 mm (0.039–0.551 in) long.

[2] Casuarina pauper was first formally described in 1989 by Lawrie Johnson in the Flora of Australia from a Ferdinand von Mueller's unpublished description of a plant he collected in the Flinders Ranges in 1851.

[5] The specific epithet (pauper) means "scanty" or "poor", referring to the habit of the species compared to C.

[4][13] Casuarina pauper produces abundant viable seed, with regeneration success likely to be inhibited during periods of insufficient soil moisture.