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weed seed identification australia

Weed identification

It is important to correctly identify a weed to ensure that it is not a native plant and that it is not a newly invasive species. Correct identification can be an important step in making sure that new weeds can be eradicated before they become established. You also have to make sure that you have the right weed to ensure that any control methods will be effective and appropriate. Factors to consider when identifying weeds include:

  • where and when the weed is growing
  • what group the weed belongs to (i.e. herb, grass, shrub, tree, vine, water plant)
  • leaf shape, size, and colour of the weed
  • flower, seed head or fruiting body of the weed

If you cannot identify a weed using booklets, fact sheets or websites, correct identification can be gained by sending a sample to the Queensland Herbarium. The Queensland Herbarium's website provides information about collecting and preparing plant specimens for identification.


A long-lived grass with creeping stems that form dense mats of vegetation. Its leaves are short and become coarse-textured with age. Its small seed-heads remain hidden within the leaf sheaths and seeds are rarely formed.

Widely naturalised southern and eastern Australia (i.e. in southern and central Queensland, eastern New South Wales, the ACT, Victoria, Tasmania, many parts of South Australia and south-western Western Australia). Also occasionally naturalised in the southern parts of the Northern Territory and naturalised on Lord Howe Island and Norfolk Island. Also widely naturalised in other parts of the world, including in northern and southern Africa, China, tropical Asia (i.e. India, Sri Lanka, Taiwan, Papua New Guinea, the Philippines and Indonesia), New Zealand, south-western USA, Mexico, Central America (e.g. Costa Rica), South America (e.g. Colombia, Peru and Ecuador), La RĂ©union, and numerous Pacific islands (e.g. the Galapagos Islands, Melanesia, Polynesia and Hawaii).

See also  a-dub seeds

A weed of closed forests, open woodlands, grasslands, riparian areas, disturbed sites, waste areas, orchards, crops, lawns, gardens, footpaths and parks in sub-tropical and temperate regions.

A long-lived (i.e. perennial) mat-forming grass with short coarse leaves and horizontal creeping stems (i.e. stolons) with many joints (i.e. nodes). It generally grows less than 30 cm in height, but may occasionally reach up to 90 cm tall.

Kikuyu (Pennisetum clandestinum) is regarded as an environmental weed in Victoria, South Australia, Western Australia, New South Wales and Queensland.

Identifying western Australian summer weeds manual

The suite of summer weeds present in the Western Australian grainbelt comprises many different species. This makes management decisions difficult and heavily reliant on correct species identification. This booklet aims to help in the identification of the common weeds found in the Western Australian grainbelt. Several weeds present in summer, such as common sowthistle, are able to germinate and reproduce throughout the year; the most common of these have been included along with weeds present only in summer.

Starting point for identification

The starting point to narrow down and identify the majority of weeds (flowering plants) is to figure out whether they are grasses or grass-like (monocotyledons) or broadleaf (dicotyledons).

Grasses and grass-like plants can be identified by the following characteristics:

  • they have a single seed leaf (cotyledon)
  • their leaves lack a leaf stalk; each leaf consists of an upper strap-like blade and a sheathing base that encloses the stem
  • the ligule (where the leaf blade joins the leaf sheath on the upper leaf surface) is either membranous or hairy
  • their leaf veins are parallel with no single main vein
  • their roots are fibrous
  • the plants have no woody parts (herbaceous).
See also  how to find it if weeds gone to seed

The major monocotyledon families are the Poaceae (grasses), Liliaceae (lilies), Cyperaceae (sedges), Orchidaceae (orchids), Iridaceae (irises) and Alliaceae (onions).

Broadleaf plants can be identified by the following characteristics:

  • they have two cotyledons
  • their shoot system consists of –
    • a main axis (stem)
    • leaves attached to the stem at nodes

    This publication groups weeds into grasses or broadleaf (no grass-like weed species are included). Within these two broad groups, the weeds are grouped by plant family, then genus and species. Their common names are given to ensure we are all discussing the same plant.