Nassella tussock is a weed of regional and national significance because of its invasiveness, destruction of pastures, negative impacts on biodiversity and difficulty to control. It can reach up to 30cm tall and has thin, tightly rolled, hairless, yellow-green leaves with very fine serrations. Young flower heads have a purple tinge and turn golden as seeds ripen. These weeping flower heads break off at maturity. It generally flowers during mid to late spring, and the seeds develop in early to midsummer.
New Zealand Christmas tree
Metrosideros excelsa (Myrtaceae)
A wide-spreading evergreen tree growing up to 5-6m high, but sometimes as high as 20m. Several branches originate close to the ground. The leaves are oblong to oval bright green and smooth leaves with a felty texture beneath. Crimson bottlebrush-like flowers appear in clusters from December to January and the fruits include a white or grey velvety capsule. This tree invades coastal fynbos on moist, peaty soils in the Western Cape.
The nodding thistle grows from sea level to an elevation of about 2 500m. It is found in neutral to acidic soils. It typically grows in meadows and grasslands, heavily grazed areas such as pastures and in disturbed soil such as roadsides and building sites. It spreads rapidly in areas subjected to frequent natural disturbances such as landslides and flooding, but does not grow well in excessively wet, dry or shady conditions.
Nerium oleander (Apocynaceae)
An evergreen shrub or small tree growing up to 6m high with dark, dull-green leaves that are paler below and have distinctive veins and a prominent midrib. Pink, red or white flowers which are slightly aromatic, with a single row of petals, appear from September to March. It bears reddish-brown fruit follicles which are finger-like and 10-20cm long. They are ridged and split longitudinally into two halves with seeds that have tufts of hairs. The whole plant is highly toxic and lethal and the sap is a skin irritant.
Orange Jessamine is a small, tropical, evergreen tree or shrub growing up to 7 m tall. The plant flowers throughout the year. Its leaves are glabrous and glossy, occurring in 3-7 oddly pinnate leaflets which are elliptic to cuneate-obovate to rhombic.
Bauhinia variegata (Fabaceae)
The orchid tree grows up to 6-10 m high. The leaves are thick and deeply divided into two lobes approximately 100mm long. Flowers are pink blotched or striped with red, cream or purple with narrow, non-overlapping petals. Flowers from August to October and produces dark brown pods.
Cortaderia selloana (Poaceae)
Vigorous, tussock grass up to 3,5m in diameter, with flowering stalks up to 4m high. Greyish- or bluish-green leaves with rough margins. Silvery-white to pink or mauve, feathery inflorescences appear from February to April. This grass invades river banks and seasonally wet habitats
Myriophyllum aquaticum (Haloragaceae)
A spirally leafed, aquatic plant capable of forming dense infestations in waterways with pale green, finely divided, feather-like leaves arranged in whorls. Tiny, solitary, inconspicuous cream flowers forming in the axils of the leaves from May-September. It invades still or slow-moving water on the banks of rivers, lakes and ponds.
Echium plantagineum (Boraginaceae)
A deep-rooted biennial up to 1m high. The leaves and stems are covered with coarse, white hairs. The stem leaves are long and small and the basal rosette leaves are broad and large with prominent lateral veins. Blue or purple flowers appear from October to April. This plant is poisonous and invades cultivated land, pastures and roadsides.
Patula pine is a coniferous tree which grows to a height of 30 m or more and attains a diameter at breast height of up to 1.2 m. It can rapidly invade grassland and shrub land where they can compete with native plants, affect fire and hydrological regimes.