Cyanothamnus rigenss, commonly known as the stiff boronia,[2] is a plant in the citrus family Rutaceae and is endemic to south-eastern New South Wales in Australia.

It is a low, compact shrub with mostly trifoliate, glandular leaves and white to pale pink, four-petalled flowers in the leaf axils.

[4][5] In 1929 Edwin Cheel gave it the name Boronia rigens and published the description in Journal and Proceedings of the Royal Society of New South Wales.

[6][7] In a 2013 paper in the journal Taxon, Marco Duretto and others changed the name to Cyanothamnus rigens on the basis of cladistic analysis.

[3] Cyanothamnus rigens grows in heath and forest, sometimes on stabilised dunes between Bombala and Mt Coricudgy east of Rylstone.