A number of plants encountered during bush regeneration work are potentially dangerous.
Rhus (Toxicodendron succedaneum, previously Rhus succedanea) is a highly toxic, allergy-causing tree. It was once common in Australian gardens because of its brilliant autumn foliage. Scattered plants still occur in gardens and seeds are spread into bushland by birds.
It is a declared Noxious Weed in New South Wales & South Australia.
It is a small, deciduous tree, 5–8 m tall with smooth grey bark. The leaves are divided into 9–15 leaflets (mostly 11) arranged in pairs with a single leaflet at the end, forming a leaf frond 20–35 cm long. The leaflets are 4–10 cm long and 2–3 cm wide. They are bright green above and often greyish beneath. In autumn they change to a brilliant red before they fall.
Rhus may be mistaken for the Chinese pistachio (Pistacia chinensis) which is also planted for its brilliant autumn foliage. They are easily distinguished as rhus leaf fronds end in a single leaflet while those of Chinese pistachio end in a pair of leaflets.
Rhus can cause painful allergic reactions to people who come into contact with the plant, its sap, and even smoke made by burning the plant material. The sap causes the worst reaction; however, contact with any part of the tree can result in symptoms. For highly sensitive people just standing under a tree can be enough to produce a reaction.
It causes severe dermatitis beginning with a rash, redness, itching and blisters wherever skin comes into contact with the plant or its sap. The rash is often accompanied by localised swelling of the face, arms and legs. Symptoms can last 7 to 10 days. Chronic sufferers may have more extreme symptoms over a longer period of time. Some cases have required hospitalisation.
The plant can be removed using the standard techniques but great care should be taken by those carrying out the work. Personal protective equipment such as overalls, hats, protective eyewear or face shields, dust masks and gloves should be used by operators, even when dealing with small seedlings. The risk of contact with sap can be reduced by waiting until after the leaves have fallen in winter before attempting to remove plants.
Take care with the disposal of material from Rhus. Even dead, dried branches can still have enough sap to cause problems.
Cator Oil (Ricinus communis) is a common weed of disturbed areas. It is a small shrub growing up to 12 metres with deeply lobed palmate leaves. Photos can be found here.
The seeds contain ricin which is highly toxic. The rest of the plant is not toxic.
Phoenix is a genus of 14 species. Phoenix canariensis, the Canary Palm, is well known in Australia, having been used as a landscape feature tree for many years and is found in parks and street plantings. The seeds spread readily and they frequently appear in bushland.
The pinnate leaves, 1 to 6 metres long, of all species have lower leaf segments that develop into long, vicious spikes known as acanthophylls. These spikes are very sharp and easily penetrate protective clothing including thick leather gloves. They can penetrate deeply, often break off leaving the tip embedded, and can transport bacteria into the wound. Infections following palm leaf wounds can be serious and have caused deaths.