kanooka, water gum
NZ Myrtaceae Key - Online edition
Tristaniopsis laurina (Sm.) Peter G.Wilson & J.T.Waterh.
Eastern Australia: Queensland, New South Wales, Victoria.
Easily propagated from seed and available in nurseries. Present in New Zealand as street trees, shelter, and in parks or gardens; occasional records of naturalised seedlings.
Recorded in main centres in lowland areas of the North Island, and from Richmond to Takaka in the South Island of New Zealand.
Trees from 5–15(–35) m tall. Grows slowly in cultivation and rarely attains maximum size.
Bark pale, smooth, papery, shedding in strips. Young branchlets and stems hairy, 4-angled.
Flower clusters 7–17 flowered. Flowers ± 10–15 mm in diam., flower stalks ± 1–2 mm long, petals 5, yellow, rounded with a narrow base, 4–5 mm long, 3–4 mm wide, hairy on the outside; sepals 5, brown, ± 1 mm long, triangular, tips free, persistent, hairy; stamens white to cream, united into 5 groups opposite the petals, shorter than the petals. Main flowering period: summer.
Tristaniopsis laurina is susceptible to myrtle rust (caused by Austropuccinia psidii).
Tristaniopsis is a genus of about 40 species in Southeast Asia, New Guinea, New Caledonia, and Australia. There is one record of a cultivated T. collina Peter G.Wilson & J.T.Waterh. from Auckland, but mainly T. laurina is known to be present in New Zealand.