Rhus tree

How to identify a rhus tree

Rhus has compound leaves up to 35 cm long, made of 9 to 15 pointed leaflets set in pairs with a single leaflet at the tip. The leaflets are bright green above and often greyish underneath, and they turn bright red, scarlet or crimson before dropping in autumn. Small cream to greenish flowers appear in long clusters in spring. Female trees then carry hanging bunches of round, fawn, papery fruit 5 to 11 mm across. The trunk has smooth grey bark. Chinese pistachio looks similar, but its leaves end in a pair of leaflets instead of a single one.

Growing a rhus tree in Brisbane

Brisbane City Council records rhus as sparingly naturalised in South East Queensland, where it can turn up in gardens, roadsides, waste areas and the edges of urban bushland. Birds eat the fruit and drop the seeds, and large numbers of seedlings can sprout under a female tree. Brisbane City Council lists it as pest vegetation. Given the health risk, it is a poor choice anywhere people walk, play or work in the garden.

What to watch out for

All parts of a rhus tree contain a resin that can cause severe allergic dermatitis: an itchy rash, redness, blisters and swelling of the face, arms or legs. Some people react just from standing near the tree, and reactions can get stronger with each exposure. Symptoms can take 12 hours to 7 days to show and last 10 to 14 days. The resin can stay on shoes, tools and clothing for up to a year. If someone reacts, call the Poisons Information Centre on 13 11 26, or 000 in an emergency.

• Irritant sap or hairs. All parts of the tree carry a resin that can cause severe dermatitis with itching, blisters and swelling, including contact with dead branches or smoke from burning it.
• Allergies. Some people react just from standing near a rhus tree, and sensitivity can increase with each exposure.
• Seedlings. Birds spread the seeds, and large numbers of seedlings can come up under female trees.

Pruning and care

Avoid pruning or handling it yourself, because contact with the sap, resin or even dead branches can set off a reaction. If the tree has to go, NSW biosecurity advice is to remove it in winter, when it is bare and sap levels are lowest, and to treat the stump so it cannot regrow. Do not mulch, chip or burn any part of it: the resin stays active for months and the smoke is toxic. Bury the material or send it to landfill, and clean tools afterwards. This is a job for a professional with full protective gear.

• Tree removal