The Port Jackson Pine is a small tree that may reach a height of 15 metres with a canopy spread to up to several metres wide. Mature trees have an attractive pyramid shape.
It has a mainly coastal distribution in NSW, growing in disjunct pacthes from Grafton to the Victorian border, and inland to about Mudgee. It grows in the extremes of north-eastern Victoria, then somewhat funnily, it grows very disjunctly and commonly in western Victoria in mallee-scrub. It extends into South Australia as far west as Kangaroo Island. It also grows on the islands of Bass Strait and the eastern parts of Tasmania. In Queensland, it extends up the coast and inland to just north of Rockhampton.
It is found in sandstone-dry sclerophyll forests and woodlands as well as sandy mallee scrub and close to wet sclerophyll forests – often on sandy soils.
Callitris is a genus of pines. Hence they do not bear flowers but rather cones (conifers); part of the group of plants called ‘gymnosperms’ (naked-seed).
Callitris spp. have mature scale leaves (sometiomes referred to as awl-shaped or awls in pines); produced in whorls of 3. The tip are often triangular and the mid-section keeled or raised. The base of leaves are usually overlapped by the tips of the next whorl of leaves below. Juvenile leaves are more needle-like and arranged in whorls of 4. In this species, the foliage may be dark green or have a bluish tinge, with leaves to 3 mm long and keeled. Leaves link together to produce long sections of foliage. Juvenile leaves are to 4 mm long.
Callitris spp. produce seed-bearing cones – the female part; and the male cones (or strobili) which produce the pollen. In this species, the male cones are produced at the terminals of the foliage (in large numbers), each about 5 mm long and only 2 mm wide, brown in colour, releasing dust-like pollen (At the right time, and on a windy day, trees can be observed releasing large amounts of ‘dust’). Females cones are very distinctive in this genus, consisting of a whorl of 6 to 8 woody valves which open in a circle, producing a star-like cluster. Female cones receive wind-blown pollen to produce seeds. In this species, woody cones are produced in clusters on the foliage, on short peduncles, woody and to 20 mm wide, with 6 valves/scales. Male and female cones are carried on the same plant. Mature female cones remain, on the branch, for many years. The female cones illustrated are at least five years old. They form as attractive feature.
The seeds have wing and are sticky/resinous, about 5 mm long.
C. rhomboidea is said to be the most ornamental of the native cypresses. Use as a “stand alone” specimen or in a hedge or screen are some of the domestic uses of this most attractive tree. The dense foliage will provide safe nesting sites for small native birds.
C. rhomboidea, once established, in common with other native species, are tolerant of drought. This makes them ideal substitutes for exotic cypresses that come from areas with high rainfall. However, this does make them more susceptible to our prolonged droughts.
Plants do not respond too well to pruning and can eventually suffer from dieback and hold a lot of dead wood. However, they can be pruned when young to shape.
This species persists in the modified residential sanstone gully in Sylvania (southern-Sydney) where I live and I have a few on the driveway. Neighbouring properties also have the odd one here and there and there are some large ones in the small bushland reserves in our neighbourhood. Hence, I have tried to incorporate them into the garden. They can produce a lot of dead wood eventually and pruning does not seem to re-invigorate them. I may have to try cutting plants down to a low trunk and see what happens. Otherwise, the foliage makes a nice contrast.
Propagate from seed.
The timber has proved to be termite resistant but is not plentiful enough to be of any particular economic importance.
Callitris rhomboidea is known as the Port Jackson Pine or Oyster Bay Pine. The common name depends on the location of the species. The former name refers to populations in NSW whist the latter common name refers to those in Tasmania.
Callitris species regenerate mostly from seed after fire.
Callitris is a genus of about 19 species occurring in Australia and New Caledonia. Australia has about 17 species, occurring in all states. New South Wales currently has 11 species.
Callitris – From the Ancient Greek – Callos (κάλλος) – meaning “beautiful” (which is changed to κάλλη to describe a noun) and –tris – Greek for “3” (τρία) – referring to the attractive manner in which the small leaves are arranged in whorls of 3.
rhomboidea – Latin – rhomboid – referring to the rhomboidal shape of the scales on cones.
This species is not considered to be at risk of extinction in the wild but is not often seen in large numbers.
NSW Flora Online (PlantNET) – Callitris rhomboidea profile page https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Callitris~rhomboidea
Gardening with Angus – Callitris rhomboidea profile page https://www.gardeningwithangus.com.au/callitris-rhomboidea-oyster-bay-pine/
Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers, Pty. Ltd. Australia.