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 Management Similar Species

Scientific Name

Cenchrus macrourus (Trin.) Morrone

Synonyms

Pennisetum macrourum Trin.

Family

Gramineae (South Australia)
Poaceae (Queensland, New South Wales, the ACT, Victoria, Tasmania, Western Australia and the Northern Territory)

Common Names

African feather grass, African feathergrass, bedding grass, beddinggrass, fountain grass, waterside reed

Origin

Native to tropical and southern Africa (i.e. Ethiopia, Somalia, Sudan, Kenya, Tanzania, Uganda, Cameroon, Gabon, Zaire, Guinea, Nigeria, Togo, Angola, Malawi, Zambia, Zimbabwe, Botswana, South Africa and Swaziland) and the Arabian Peninsula (i.e. Yemen).

Naturalised Distribution

A widely naturalised species that has a somewhat scattered distribution in the southern regions of Australia. It is relatively common in the Sydney region in New South Wales, in southern Victoria, in south-eastern South Australia and in the coastal regions of south-western Western Australia. Also present in other parts of coastal and sub-coastal New South Wales and in Tasmania.

Naturalised overseas in New Zealand and south-western USA (i.e. California).

Habitat

This species is mostly a weed of temperate regions and inhabits waterways, roadsides, waste areas, pastures, grasslands and open woodlands.

Habit

An upright (i.e. erect), long-lived (i.e. perennial), grass usually growing 1-1.8 m tall, but occasionally reaching up to 2 m or more in height. It forms large clumps and also spreads via long creeping underground stems (i.e. rhizomes).

Distinguishing Features

• an upright and long-lived grass that forms large clumps and usually grows 1-1.8 m tall.
  
  
• its linear leaves are mostly hairless, and sometimes have purplish edges.
  
  
• its long spike-like seed-heads (6-40 cm long and 1-2 cm across) are mostly green or yellowish in colour with a tinge of either purple, yellow or brown depending on their age.
  
  
• these seed-heads consist of large numbers of densely packed flower spikelets each surrounded by several feathery bristles (mostly 5-10 mm long).
  
  
• its mature seed-heads and seeds turn straw-coloured as they mature.
  
  
• seeds are shed still surrounded in the finely-barbed feathery bristles.

Stems and Leaves

Several tall flowering stems (i.e. culms) are produced from the base of the plant (i.e. the crown). These are unbranched, rounded and hairless (i.e. glabrous). The creeping underground stems (i.e. rhizomes) are up to 7 mm thick and 2 m long and give rise to shoots and roots.

The leaves consist of a leaf sheath, which partially encloses the stem, and a spreading leaf blade. Leaf sheaths are sparsely hairy (i.e. puberulent) and strongly ribbed on the upper surface, while the linear leaf blades (10-50 cm long and 2-13 mm wide) are also mostly hairless (i.e. glabrous). The upper leaf blade surfaces are light green, sometimes with purplish edges, while the lower surfaces are darker green. Young leaves are inrolled but they become flattened as they mature. Where the leaf sheath meets the leaf blade there is a fringe of tiny hairs (i.e. ciliate ligule) 0.5-1.5 mm long.

Flowers and Fruit

The long spike-like (i.e. spiciform) seed-heads are actually panicles with numerous very short branches closely held to the stalk. These seed-heads (6-40 cm long and 1-2 cm across) are held upright (i.e. erect) or have a somewhat drooping appearance. They are mostly green or yellow in colour when young and can have a tinge of purple, yellow or brown depending on their age (i.e. stigmas are purplish, young stamens are yellow and older stamens turn brown in colour). Large numbers of densely packed flower spikelets (2-7 mm long) are borne on these seed-heads and each is surrounded by finely-barbed (i.e. scabrous) feathery bristles (mostly 5-10 mm long, but occasionally up to 20 mm long). Flowering occurs during late spring and summer.

The seed-heads and seeds turn yellowish-brown or straw-coloured as they mature. Each seed (5-7 mm long) and is shed from the seed-head still surrounded by the cluster of (i.e. involucre) feathery bristles.

Reproduction and Dispersal

This species reproduces by seed and also via creeping underground stems (i.e. rhizomes).

The bristly seeds are dispersed by animals, water, wind and also become attached to clothing and vehicles. Infestations can quickly increase in area via the creeping underground stems (i.e. rhizomes), which can also be spread larger distances by cultivation equipment, other machinery, and in dumped garden waste.

Environmental Impact

African feather grass (Cenchrus macrourus) is regarded as an environmental weed in Victoria, Western Australia, South Australia, New South Wales and Tasmania. It was also recently listed as a priority environmental weed in two Natural Resource Management regions.

Legislation

This species is declared under legislation in the following states and territories:

• New South Wales: Class 5  - a restricted weed which must not be sold, bought or knowingly distributed (throughout the entire state).
  
  
• South Australia: 3* - declared in Class 3, a designation for agricultural weeds. This species is required to be controlled in part of the state only.
  
  
• Tasmania: D - the importation or sale of this species is prohibited and measures to reduce its population in an area, eradicate it from an area, or restrict it to a particular area may be required.
  
  
• Victoria: P3 - prohibited and must be eradicated or controlled (in the Mallee, Glenelg and North Central regions), and C1 - all reasonable steps must be taken to control the weed and prevent its spread (in the Port Phillip West region only).
  
  
• Western Australia: Prohibited - on the prohibited species list and not permitted entry into the state.

Management

For information on the management of this species see the following resources:

• the Victorian Department of Primary Industries Landcare Note on this species, which are both available online at http://www.dpi.vic.gov.au.
  
  
• the Tasmanian Department of Primary Industries and Water Weed Service Sheet on this species, which is available online at http://www.dpiw.tas.gov.au.

Similar Species

African feather grass (Cenchrus macrourus) is very similar to mission grass (Cenchrus polystachios), Deenanth grass (Cenchrus pedicellatus) and swamp foxtail (Cenchrus purpurascens) and relatively similar to elephant grass (Cenchrus purpureus), fountain grass (Cenchrus setaceus) and feathertop (Cenchrus longisetus). These species can be distinguished by the following differences:

• African feather grass (Cenchrus macrourus) is a large long-lived (i.e. perennial) grass (usually 1-2 m tall) with very elongated, greenish or yellowish-coloured seed-heads. The main stem (i.e. rachis) of the seed-head is rounded and the relatively short bristles (mostly less than 10 mm long) are rough (i.e. scabrous).
  
  
• mission grass (Cenchrus polystachios) is a large long-lived (i.e. perennial) grass (usually 2-3 m tall) with very elongated, yellowish or brownish-coloured seed-heads. The main stem (i.e. rachis) of the seed-head is angular and the relatively long  bristles (4-25 mm long) are hairy (i.e. plumose).
  
  
• Deenanth grass (Cenchrus pedicellatus) is a moderately-sized short-lived (i.e. annual or perennial) grass (usually 30-150 cm tall) with elongated, pale purplish-coloured seed-heads. The main stem (i.e. rachis) of the seed-head is angular and the relatively long bristles (6-24 mm long) are hairy (i.e. plumose).
  
  
• swamp foxtail (Cenchrus purpurascens) is a moderately-sized long-lived (i.e. perennial) grass (usually 60-100 cm tall) with relatively elongated, purplish-coloured seed-heads. The main stem (i.e. rachis) of the seed-head is rounded and the relatively long bristles (15-30 mm long) are hairless (i.e. glabrous).
  
  
• elephant grass (Cenchrus purpureus) is a very large and robust long-lived (i.e. perennial) grass (1-7 m tall) with elongated, greenish or purplish-coloured seed-heads. The main stem (ie.. rachis) of the seed-head is rounded and the relatively long bristles (10-16 mm or more long) are rough or hairy (i.e. scabrous to plumose).
  
  
• fountain grass (Cenchrus setaceus) is a moderately-sized long-lived (i.e. perennial) grass (50-150 cm tall) with relatively elongated, reddish or pinkish-coloured seed-heads. The main stem (i.e. rachis) of the seed-head is angular and the long bristles (up to 25 mm or more) are hairy (i.e. plumose).
  
  
• feathertop (Cenchrus longisetus) is a relatively small long-lived (i.e. perennial) grass (15-100 cm tall) with relatively broad, oblong-shaped, whitish-coloured seed-heads. The main stem (i.e. rachis) of the seed-head is angular and the very long bristles (30-70 mm long) are hairy (i.e. plumose).