Uncinia is a genus of flowering plants in the family Cyperaceae, known as hook-sedges in Australia[3] and as hook grasses or bastard grasses in New Zealand.

[4] The genus is characterised by the presence of a long hook formed by an extension of the rachilla,[5] which is used to attach the fruit to passing animals (epizoochory), especially birds,[6] and it is this feature which gives the genus its name, from the Latin uncinus, meaning a hook or barb.

[7] Uncinia is a "satellite genus" of the very large genus Carex, alongside other satellites such as Cymophyllus, Kobresia, Schoenoxiphium, Vesicarex.

[9] Uncinia has a Gondwanan distribution,[5] with most species found Australia, New Zealand and South America,[3] as far north as Mexico and Jamaica.

[12] Smaller numbers of species are also found in New Guinea, Borneo, the Philippines, Hawaii, Tristan da Cunha, Kerguelen, Île Amsterdam, Île Saint-Paul, and the Prince Edward Islands, although none are known from the mainland of Africa.