Diplarrena Genus

Diplarrena is a small genus of flowering plants in the family Iridaceae (order Asparagales), comprising just two species, both endemic to southeastern Australia — recorded across New South Wales, Tasmania, and Victoria. The genus was described by Jacques Labillardière and published in 1800.

Plants are tufted perennial herbs growing from short rhizomes. Their basal leaves are linear and flat, remaining present year-round, while the erect flowering stems carry only a few reduced leaves. Flowers open one at a time from a green terminal spathe. Though iris-like in general form, the flowers are distinctly zygomorphic (bilaterally symmetrical) rather than radially symmetrical, with six white tepals and a style bearing two thread-like branches.

The defining botanical feature of the genus is its stamens: Diplarrena flowers have only two functional stamens, whereas every other genus in the Iridaceae family has three. This distinction is reflected directly in the genus name, which derives from the Greek diploos ("double") and arren ("male"). The name has a long history of misspelling as "Diplarrhena," an error traced back to George Bentham's influential 1873 work Flora Australiensis.

In cultivation, Diplarrena is grown as an ornamental for its neat, grass-like foliage and delicate white flowers. At least one named cultivar exists, 'Amethyst Fairy,' a large-flowered selection distinguished by darker markings on its inner tepals.