Stenostachys is a small genus endemic to New Zealand, and it is currently known to have three species. Ever since the Russian botanist Николаи Степанович Туржанинов established Stenostachys narduroides Turcz as a model species in 1862, it has long been an old genus that has not been recognized by morphology-based biosystems and taxonomy scholars. Because cytogenetics and molecular genetics have proved that it is a unique heterotetraploid plant with a special combination of H and W genomes, it has been recognized by scholars today more than 140 years later.