Weeds of Australia - Fact Sheet

Top Scientific Name Synonyms Family Common Names Origin Naturalised Distribution Habitat Habit Distinguishing Features Stems and Leaves Flowers and Fruit Reproduction and Dispersal Environmental Impact Legislation Similar Species

Scientific Name

Solanum nigrum L.

Synonyms

Solanum nigrum L. subsp. nigrum
Solanum nigrum L. subsp. schultesii (Opiz) Wessely
Solanum opacum A. Braun & Bouché (misapplied)
Solanum schultesii Opiz

Family

Solanaceae

Common Names

black berry nightshade, black fruited nightshade, black nightshade, blackberry, black-berry night shade, black-berry nightshade, blackberry nightshade, common nightshade, deadly nightshade, garden huckleberry, garden nightshade, harsh, hound's berry, inkberry, nightshade, nightshade black-berry, poisonberry, potato bush, tomato bush, wild currents

Origin

Native to north-western Africa (i.e. Algeria, Morocco and Tunisia), Europe, western and central Asia (i.e. Afghanistan, Iran, Lebanon, Syria, Turkey, Armenia, Azerbaijan, Georgia, western Russia, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan), China, and the Indian Sub-continent (i.e. northern India, Nepal and Pakistan).

Naturalised Distribution

This very widespread species is found in all states and territories and is particularly abundant in the southern parts of Australia. It is widely naturalised in Queensland, New South Wales, the ACT, Victoria, Tasmania, South Australia and Western Australia. Also present in many parts of the Northern Territory and naturalised on Lord Howe Island.

Wide naturalised in tropical and southern Africa, Madagascar, eastern Asia (e.g. Japan and Taiwan), New Zealand, North America (i.e. Alaska, the USA, Canada and Mexico), Central America (i.e. Costa Rica, El Salvador, Honduras and Panama), the Caribbean, South America (i.e. Chile, Colombia and Peru), Mauritius, and on several Pacific islands (e.g. Guam, New Caledonia and Hawaii)

Habitat

A common weed of crops, pastures, orchards, vineyards, roadsides, gardens, disturbed sites and waste areas in temperate, sub-tropical, tropical and semi-arid environments.

Habit

A short-lived (i.e. annual or short-lived perennial) herbaceous plant or small shrub growing up to 1.25 m tall. It is usually upright (i.e. erect) in habit, but plants may become spreading with age.

Distinguishing Features

• a bushy or herbaceous plant growing up to 1.25 m tall.
  
  
• its stems are rough in texture and its leaves are slightly hairy or hairless.
  
  
• its small star-shaped flowers are white (often tinged with purple) and borne in small clusters in the leaf forks.
  
  
• its fruit are dull green when young, turning purplish-black and remaining dull in nature as they mature.

Stems and Leaves

Stems are sparsely hairy (i.e. puberulent), or occasionally hairless (i.e. glabrous), and are rough in texture. They are green or purplish-green when young.

The alternately arranged leaves (2-13 cm long and 1-8 cm wide) are borne on stalks (i.e. petioles) 5-30 mm long. Leaf blades are oval (i.e. elliptic), elongated (i.e. lanceolate) or egg-shaped in outline (i.e. ovate) and taper to a point at the tip (i.e. acute or acuminate apex). Their margins are either entire, bluntly toothed (i.e. crenate), or slightly lobed (i.e. sinuate). They are sparsely hairy (i.e. puberulent) on both surfaces.

Flowers and Fruit

The small star-shaped flowers (7-12 mm across) are borne in several-flowered clusters in the leaf forks (i.e. axils) near the tips of the branches. These flower clusters have a main stalk (i.e. peduncle) 1-2 cm long and each flower also has its own stalk (i.e. pedicel) 7-11 mm long. The flowers have five white or purple-tinged petals (3.5-4.5 mm long), that are fused together at the base, and a yellow central cone. They also have five small greenish sepals (1.5-2.5 mm long), five yellow stamens (about 2.5 mm long), and an ovary topped with a style and stigma. Flowering occurs throughout the year.

The rounded fruit (i.e. globular berries) turn from green to dull black or purplish-black in colour when mature. These fruit (5-8 mm across) are generally borne pointing downward (i.e. deflexed) with sepals that generally point outwards. They contain numerous small seeds (about 1.5 mm long by 1 mm wide).

Reproduction and Dispersal

This species reproduces mainly by seed, which are most often spread by birds and other animals that eat the fruit.

Environmental Impact

Blackberry nightshade (Solanum nigrum) is regarded as an environmental weed in Victoria, Western Australia, New South Wales, Queensland and the Northern Territory.

Legislation

Not declared or considered noxious by any state government authorities.

Similar Species

Blackberry nightshade (Solanum nigrum) is very similar to glossy nightshade (Solanum americanum), and intermediates between the two species are sometimes seen. However, blackberry nightshade (Solanum nigrum) can typically be distinguished by its relatively dull fruit with smaller outward pointing sepals. Its flowers are also arranged in slightly elongated clusters, and its fruit are generally borne pointing downwards.

Blackberry nightshade (Solanum nigrum) is also similar to hairy nightshade (Solanum chenopodioides), cherry nightshade (Solanum physalifolium var. nitidibaccatum) and the native greenberry nightshade (Solanum opacum). These species can be distinguished by the following differences:

• blackberry nightshade (Solanum nigrum) has almost hairless leaves and stems. Its fruit are usually very glossy in appearance and turn black or purplish-black as they mature.
  
  
• hairy nightshade (Solanum chenopodioides) has very hairy leaves and stems. Its fruit are dull in appearance and turn black as they mature.
  
  
• cherry nightshade (Solanum physalifolium var. nitidibaccatum) has somewhat hairy leaves and stems. Its fruit are usually glossy in appearance and green to purplish green when mature.
  
  
• greenberry nightshade (Solanum opacum) has somewhat hairy leaves and stems. Its fruit are usually glossy in appearance and are green or whitish-green when mature.

Note: For a more in-depth key to distinguish between all of the solanums (Solanum spp.) present in eastern Australia, see the online key to the Solanum Species of Eastern Australia at http://delta-intkey.com/solanum/index.htm.