Nitraria, commonly known as the nitre bushes, is a genus of approximately nine species of flowering shrubs in the family Nitrariaceae, order Sapindales. The genus has a broad geographic range spanning the western Sahara east through Central Asia, and extends south into Australia, with scattered occurrences across Africa and Europe.
Plants in this genus are shrubs, often thorny (spinose) and clothed in fine hairs (pubescent). The leaves are alternate or clustered, simple, and somewhat fleshy (semisucculent), with minute stipules that fall early. Flowers are borne in dichasial cymes and are actinomorphic and bisexual, though they often function as unisexual. Each flower has a persistent 5-lobed calyx, five (rarely six) hooded petals arranged in an induplicate-valvate pattern, and 10–15 stamens. The superior ovary has three locules, each containing a single pendulous ovule.
The fruit is a drupe with a fleshy outer layer (exocarp) enclosing a hard bony stone (putamen) that is ovoid-conical in shape, marked by irregular pits on the lower portion and six longitudinal furrows toward the apex. The single seed lacks endosperm. The genus has historically been placed within Zygophyllaceae but is now recognised in its own family, Nitrariaceae.
Distribution
The genus ranges from the western Sahara across North Africa, the Middle East, and Central Asia, extending into Russia and reaching Australia, where one or two species grow across all mainland states. Isolated populations also occur in parts of Europe.
Taxonomy Notes
Nitraria was historically placed within the family Zygophyllaceae but is now segregated into its own family, Nitrariaceae, within the order Sapindales. GBIF recognises it as an accepted genus.
Ecology
Nitraria species grow in arid and semi-arid habitats, including saline flats and desert margins. Their semisucculent leaves and spinose habit are typical adaptations to dry, often saline environments.
