Weed Alert: African feather grass

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African feather grass declarations


 

 

Contacts and Further Information

If you find this weed contact your local Council Weeds Officer or the nearest Department of Primary Industries office for positive identification and further assistance.

Alternatively call the NSW NSW Invasive Plants and Animals Enquiry Line on
1800 680 244 or send an email to weeds@dpi.nsw.gov.au









NSW No Space 4 Weeds

African feather grass (Pennisetum macrourum)

World Status | Identification | Growth and Spread | Control | Legislation

African feather grass is a highly invasive clump forming perennial grass, that has the ability to spread rapidly due to a vigorous rhizome system. It can form dense infestations that completely eliminate all other plants.

Young plants are very ornamental and in the past were planted in gardens. It is found along banks of rivers and creeks, roadsides and waste areas where adequate moisture is available. Large infestations present a significant fire hazard, reduce biodiversity and block access to waterways.

World Status

African feather grass is native to South Africa. It is a serious weed in New Zealand and small areas have been reported in New South Wales, Victoria, Tasmania, South Australia and Western Australia. The impact in Australia at present is minimal with only isolated infestations.

Identification

African feather grass is an erect perennia grass, sometimes over 2 m high.

Stems

The stems are erect, unbranched and cylindrical.

Leaves

The light green leaves grow to 1.2 cm wide and are ribbed on the upper surface. They are a darker green on the lower surface and sometimes purplish along the edges and tips. The leaves grow from the base of the plant to 1.2 m high, are slightly curled and sometimes drooping. They emerge inrolled, later becoming flattened but the tips remain inrolled. In cross section, the leaves are slightly curved and the edge has fine serrations.

Flower

An erect or drooping long thin spike-like panicle which is a purplish yellow or brown. The spike is 10 to 40 cm long and 1 to 2 cm diameter. The seed head is made up of numerous florets that are 5 to 7 mm long and surrounded by feather-like serrated bristles mostly to 1 cm long.

Roots

African feather grass has an network of fibrous roots which grow to a depth of 1 m. It also has sturdy rhizomes about 7 mm in diameter and up to 2 m in length. The rhizomes are partly enclosed in a sheath and occur from just below the soil surface to a depth of 30 cm.

Growth and Spread

African feather grass prefers sub tropical to warm temperate climates and grows on open well drained soils. Established plants are relatively drought resistant.

Flowering takes place in late spring and summer with seeds maturing in February and March. African feather grass can spread by seed but seedlings are rarely found in the field.

Most spread is by rhizomes which grow rapidly in spring and summer, depending largely on available moisture. The rhizome develops new roots and shoots away from the parent plant, and areas can be rapidly covered in African feather grass.

Plants become dormant in winter, with new shoots being produced from rhizomes and crowns each spring.

Rhizomes are spread by cultivation equipment, road graders and other machinery. Some spread can be attributed to human interest in the plant for dried flower arrangements and for ornamental purposes in landscaping.

The bristles on the seed are well equipped to cling to clothing and bags, and to the wool and hair of animals. Seed is also spread readily by water which accounts for infestations along streams. Wind dispersal is of some local importance.

Control

Control of African feather grass requires a program involving multiple cultivations, herbicides and pasture improvement. Repeated treatments over a long period of time are required to exhaust the reserves in the rhizomes.

A key to African feather grass control is plant competition from desirable plant species with the emerging African feather grass plants. This includes perennial pastures in grazing areas and suitable shrubs or trees along waterways, waste areas and roadsides.

Legislation

Pennisetum macrourum is a Class 5 noxious weed throughout NSW under the NSW Noxious Weeds Act 1993. As a notiable weed, all outbreaks of African feather grass must be reported to the local council within three days. The responsibility for the control of noxious weeds on private land rests with the land owner or occupier of the land.

Acknowledgements

Author: John Hosking.

References

  • Hosking, J. R., Sainty, G., Jacobs, S. and Dellow, J. (in prep) The Australian WEEDbook.
  • Parsons, W.T. and Cuthbertson. E.G. (2000) Noxious Weeds of Australia 2nd ed. CSIRO publishing, pp 116–118.