Tristaniopsis laurina is commonly known as Water Gum or Kanooka. It is native to Australia, belongs to the Myrtaceae family, and is related to the eucalypts. It usually grows near the eastern coastline along the banks of streams, where the trunks and branches tend to be shaped in the direction of the current and give an indication of the flood height.

Tristaniopsis laurina has a slow rate of growth, and usually reaches 10 m tall. The tree is multi-branched, and may be pruned to maintain a compact shape. It can grow to be 30 m height in native habitats.

Flowers and fruits

The flowers are bright yellow and have a distinctive odour. They usually bloom in the late spring or early summer. They attract bees which feed on the nectar and pollen. The individual flowers are about 10 mm in diameter with five pale green sepals, five small, yellow and rounded petals, and numerous stamens united in five groups and a style.

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The flower has 5 pale green sepals, 5 yellow free petals, 5 groups of yellow stamens and a style

 

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The petals, stamens and style as seen under microscope. The colour of the petals and stamens appear paler under the microscope.
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The style is made up of stigma, style and ovary. Many ovules are found in the ovary.
The ovary is cut open showing 3 carpels with ovules inside
The ovary is cut open showing 3 carpels with ovules inside

 

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The stamens of the flowers on the right start to wither after pollination and fertilization

 

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The ovaries of the flower enlarged to form young fruit. Part of the style remains on each developing ovary.
The 3-locular ovary has been transversely cut open to show the developing seeds.
The 3-locular ovary of the fruit above has been transversely cut open to show the developing seeds.

 

The fruit finally develops into a woody capsule which is globular in shape and 6-8 mm in diameter.

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Woody seed capsules have split open to release the seeds

 

Leaves and stem

The leaves are glossy green in appearance, paler on the under surface and slightly hairy underneath. They are usually 8 to 15 cm long, 2 to 3 cm wide, oblanceolate in shape and alternately arranged.

(oblanceolate: the reverse of lanceolate, with the widest point at one-third of the leaf from the apex and tapering toward the base.)

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The leaves are glossy green in appearance, about 7 to 12 cm long, 15– 50 mm wide, oblanceolate in shape

 

The trunk is smooth with patches of scaly bark, shaded in brown and grey hues. The bark becomes scaly as the tree matures.

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The young stem has a smooth bark
The older s
The older stem has scaly bark

 

Bibliography

https://en.wikipedia.org/wiki/Tristaniopsis_laurina

https://www.anbg.gov.au/gnp/gnp10/tristaniopsis-laurina.html

http://www.hornsby.nsw.gov.au/media/documents/environment-and-waste/bushland-and-biodiversity/native-tree-database-fact-sheets/Fact-sheet-Tristaniopsis-laurina-Water-Gum.pdf

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