Top

Scientific Name
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
Print Fact Sheet
ABCDEFGHIJKLMNOPQRSTUVWYXZ

Click on images to enlarge

Photo by Harry Rose - flickr.com (CC BY 2.0)

Photo by Harry Rose - flickr.com (CC BY 2.0)

Photo by Harry Rose - flickr.com (CC BY 2.0)

Paspalum quadrifarium

Scientific Name

Paspalum quadrifarium Lam.

Family

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

Common Names

blue grass, giant paspalum, golden-top grass, goldentop grass, paspalum, tussock paspalum

Origin

Native to southern South America (i.e. Brazil, Argentina, Paraguay and Uruguay).

Naturalised Distribution

Naturalised in some parts of eastern Australia (i.e. south-eastern Queensland, some parts of eastern New South Wales and southern Victoria).

Also naturalised elsewhere, including in south-eastern USA (i.e. Mississippi).

Habitat

A weed of warmer-temperate, sub-tropical and tropical regions that is mostly found in disturbed sites, rainforests, closed forests, open woodlands and forest margins.

Habit

A tufted or tussock-forming, upright (i.e. erect), long-lived (i.e. perennial), grass usually growing 0.9-2 m tall.

Distinguishing Features

Stems and Leaves

The flowering stems (i.e. culms) are un-branched and hairless (i.e. glabrous).

The leaves are alternately arranged, with a sheath that surrounds the stem, and a long and narrow (i.e. linear) leaf blade (15-70 cm long and 4-9 mm wide). The leaf sheaths are mostly hairless (i.e. glabrous), except near where they meet the leaf blade. At this point there is a small membranous structure (i.e. ligule), about 1-4 mm long, that is surrounded by hairs. The leaf blades gradually taper to a point (i.e. attenuate apex) and are hairless (i.e. glabrous) or sparsely hairy (i.e. puberulent).

Flowers and Fruit

The elongated seed-heads (10-25 cm long) have many (15-25) side-branches (i.e. a panicle of racemes). Each of these branches (i.e. racemes) is 3-10 cm long and bears numerous (50-100) small flower spikelets. These flower spikelets (2-2.8 mm long) are paired on either side of the branch (i.e. rachis), giving the branches a four-rowed appearance. They are oval (i.e. elliptic) in shape with surfaces that are usually slightly hairy (i.e. pubescent). Flowering occurs throughout the year, but is most abundant from spring through to early autumn.

When the seeds are mature, the whole rust-coloured flower spikelet falls from the seed-head entire.

Reproduction and Dispersal

This species reproduces by seed. The seeds are most likely dispersed by water, animals, machinery and other vehicles.

Environmental Impact

Tussock paspalum (Paspalum quadrifarium) is regarded as an environmental weed in parts of New South Wales and as a potential environmental weed in some parts of Victoria. It is also listed as a priority environmental weed in at least one Natural Resource Management region.

This highly invasive species often establishes on road edges and in other disturbed sites, such as along drainage lines. It spreads from these areas into nearby bushland and along waterways. Tussock paspalum (Paspalum quadrifarium) grows in large clumps up to one square metre in size and puts pressure on bushland integrity and native species biodiversity. Once established, it has the ability to form extremely dense infestations that out-compete all other vegetation.

Tussock paspalum (Paspalum quadrifarium) is currently of most concern in the wider Sydney and Blue Mountains, where it inhabits disturbed but un-mown sites of relatively low fertility.

Legislation

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

Management

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

Similar Species

Tussock paspalum (Paspalum quadrifarium) is similar to other closely-related grasses, including Vasey grass (Paspalum urvillei), broad-leaved paspalum (Paspalum mandiocanum), paspalum (Paspalum dilatatum), Bahia grass (Paspalum notatum) and scrobic (Paspalum scrobiculatum). These species can be distinguished by the following differences: