Tristaniopsis collina, known as the Hill Water Gum or Hill Kanuka is a tree of eastern Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

. The usual habitat is rainforest

Rainforest

Rainforests are forests characterized by high rainfall, with definitions based on a minimum normal annual rainfall of 1750-2000 mm...

 away from streams on shallow soils at high altitude. However, it can occasionally be seen at low altitudes such as at Seal Rocks

Seal Rocks, New South Wales

Seal Rocks is a small coastal settlement in the Great Lakes Council Local Government Area, in the Mid North Coast/Hunter regions of New South Wales, Australia, north-north-east of Sydney...

 and Chatswood West. The Hill Water Gum is remarkably similar to the related Water Gum, however the latter species is strictly riparian.

The range of natural distribution of the Hill Water Gum is from near Mount Dromedary (36° S) in the south of New South Wales

New South Wales

New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...

 to the border with the state of Queensland

Queensland

Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...

 at the McPherson Range

McPherson Range

The McPherson Range is an extensive mountain range, a spur of the Great Dividing Range, heading in an easterly direction from near Wallangarra to the Pacific Ocean coastline. It forms part of the Scenic Rim on the border between the states of New South Wales and Queensland. Further west of the...

 (28° S).

Description

A small to medium tree, up to 35 metres in height and a stem diameter of 75 cm. The trunk is irregular, not cylindrical. The bark is grey or creamy, very thin with papery fibres that come off to touch. Branchlets are coloured purple and angular in cross section. The alternate simple leaves are around 5 to 8 cm long, with a long thin tip. Oil dots numerous and of varying sizes. The midrib is sunken on the top surface, but raised below.

Yellow flowers form in cyme

Inflorescence

An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...

s from November to January. The fruit is a dry capsule maturing from April to July. The capsule is practically identical to the capsule of the Water Gum. The winged seeds are 5 mm long and 2 mm broad.