[4] Kirk visited Great Barrier Island in late 1867, during which time he likely collected specimens of the plant.

high, spreading; young shoots and leaves white with loosely appressed silky hairs.

[3]Kirk notes that the species is similar to K. ericoides, but the two species can be told apart due to the larger flowers of K. sinclairii, as well as the "white silky leaves" and because the "ovary is sunk fully one-third below the narrow calyx-tube, while the sepals and petals are narrower, and the style is extremely slender".

[4] K. sinclairii is estimated to cover 90.5 ha (224 acres) or 0.3% of the total land area of Great Barrier Island.

[4] Kunzea sinclairii is listed as "threatened – nationally critical" under the New Zealand threat classification series 3.