''Tristania'' is a

monotypic genus In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

of flowering plants native to

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

, Australia, closely related to '' Thaleropia''. The genus had a number of species, but some have been reclassified as ''

Lophostemon ''Lophostemon'' ('lophos' - crest, 'stemon' - stamen) is a genus of 4 species of evergreen tree in the myrtle family Myrtaceae. All four species are native to Australia, with one extending to New Guinea. The genus was first described in 1830 bu ...

'' and ''

Tristaniopsis ''Tristaniopsis'' is a group of shrub and tree in the myrtle family Myrtaceae described as a genus in 1863. They have a wide distribution in Southeast Asia, New Guinea, New Caledonia ) , anthem = "" , image_map = New Caledonia on the globe ...

''. The sole species currently in the genus is ''Tristania neriifolia''. It is known commonly as the water gum.''Tristania neriifolia''.
Australian Native Plants Society. It is a small

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

, with dense branching. The leaves are

evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, whic ...

, opposite, simple, lanceolate, 5–9 cm long and 1 cm broad. The

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...

s are produced in dense clusters of 3–15 together; each flower is 1–1.5 cm diameter, with five small yellow petals and numerous conspicuous stamens.

References

Myrtaceae Flora of New South Wales Myrtales of Australia {{Australia-rosid-stub