A small woody shrub with rough pimply-textured bark. Its alternately arranged leaves are narrowly oval or elongated and have finely toothed margins. Its bright yellow flowers (2-3 cm across) have five petals, five sepals and numerous stamens. The sepals are initially green, but they turn bright red as the fruit develop. The small fruit (5-8 mm long) turn from green to black as they mature.
This species is widely naturalised in eastern Australia. It is most common in the coastal districts of southern and central Queensland, but is also becoming relatively common in the coastal districts of northern and central New South Wales. It was also recently recorded from northern Queensland, and is naturalised on Lord Howe Island and Norfolk Island.
Mainly a weed of sub-tropical regions, but also found growing in warmer temperate and tropical environments. This species has invaded roadsides, disturbed sites, waste areas, rainforests, forest margins, riparian areas and dry sclerophyll forests that are close to habitation.
A small long-lived (i.e. perennial) shrub with an upright (i.e. erect) habit. It usually grows 1-2 m tall, but occasionally reaches up to 3 m in height.
Ochna (Ochna serrulata) is a significant environmental weed in Queensland and New South Wales, and is regarded as a potential environmental weed or "sleeper weed" in other parts of Australia.
The woody branches are rough in texture and densely covered in many tiny lumps (i.e. lenticels). Younger stems are green to bronze in colour, but turn brown with age. The alternately arranged leaves are narrowly oval (i.e. elliptic) or elongated in shape (20-60 mm long and 6-20 mm wide). They are hairless (i.e. glabrous) and have finely toothed (i.e. serrate) margins. The length of leaf stalks varies, some leaves are almost without leaf stalks (i.e. sub-sessile) while others have stalks (i.e. petioles) up to 13 mm long. Young leaves often have a bronze tinge or are light green, while older leaves are dark green in colour.
The showy, but short-lived, bright yellow flowers (2-3 cm across) are borne singly on short stalks (i.e. pedicels) 1-2 cm long. These flowers have five bright yellow petals (9-13 mm long) and numerous large stamens. The five sepals are green (6-7 mm long at flowering time), but as the fruit develop the sepals enlarge and turn bright red in colour. Flowering occurs mostly during spring and summer. A ring of up to six shiny, oval (i.e. ellipsoid) fruit develop on the central area of the flower (i.e. the receptacle). These single-seeded fruit (5-8 mm long) look like berries (they are actually drupes) and change colour from green to black as they mature.
This plant reproduces mainly by seed. Its brightly coloured fruit are readily eaten and dispersed by birds and other animals. They may also be dispersed in dumped garden waste.
Ochna (Ochna serrulata) is a very distinctive plant, especially when in flower and fruit, and is rarely confused with other native or naturalised species in Australia. However, it is very similar to Mickey Mouse plant (Ochna kirkii), a garden plant that has become naturalised in other parts of the world. These two species can be distinguished by the following differences: ochna (Ochna serrulata) has relatively small leaves (2-6 cm long) that are elongated or narrowly oval (i.e. elliptic) in shape. Its flowers are relatively small (2-3 cm across), with petals 9-13 mm long.Mickey Mouse plant (Ochna kirkii) has relatively large leaves (5-10 cm long) that are egg-shaped in outline (i.e. obovate), oval (i.e. elliptic) or broadly oblong in shape. Its flowers are relatively large (3.5-5 cm across), with petals 15-25 mm long. The native hairy clerodendrum (Clerodendrum tomentosum) has a similar fruit to ochna (Ochna serrulata). However, it has only a single berry on its red receptacle instead of a cluster of 4-6 berries, and its leaves are velvety hairy (i.e. tomentose).