Quick Facts

Quick facts

• Para Grass (Urochloa mutica) is a perennial grass with creeping stems that develop new roots at the nodes.
• It mostly grows in freshwater wetlands, along the margins of streams and lakes and on floodplains.
• It is naturalised in tropical and subtropical parts of Australia, in northern New South Wales, Queensland, the Northern Territory and northern Western Australia.
• Para Grass mainly spreads through broken stem pieces that can float in the water and grow into a new plant.
• Para Grass invades native wetlands and can alter fire regimes and increase sedimentation. It is a serious weed in sugarcane fields.
• Para Grass can be controlled by intensive grazing, slashing or herbicide application.

What Does It Look Like?

What is it?

Para Grass (Urochloa mutica) is a perennial grass that grows up to 1 m tall, although the creeping stems can be longer. The stems are hollow and robust. They often develop new roots at the lower nodes. If growing along deep water, stems can float on the water surface and form thick mats. The leaf sheaths and nodes are densely hairy. The leaf blades are up to 20 cm long and up to 2 cm wide and dark green (Stephens & Dowling 2001; Smith 2002; Queensland Department of Agriculture, Fisheries and Forestry 2013).

The flowering stem is up to 18 cm long, consisting of 10–30 spikelike branches that are 2–8 cm long. The individual flower spikelets are 3–3.5 mm long and hairless (Queensland Department of Agriculture, Fisheries and Forestry 2013; Northern Territory Department of Land Resource Management).

For further information and assistance with identification of Para Grass contact the herbarium in your state or territory.

Flower colour

Purplish to green.

Growth form (weed type/habit)

Grass

Where it currently grows? Preferred habitat

Para Grass is adapted to moist regions in the tropics and subtropics. It is mostly found in areas with 1,000 mm rain per year or more. It grows in freshwater wetland habitats, but tolerates brackish water as well. Para Grass prefers disturbed habitats with low tree cover, but is relatively shade tolerant. Common habitats are the margins of streams and lakes, floodplains, but also disturbed sites in rural and urban areas. Para Grass is a serious weed in sugarcane fields (Northern Territory Department of Land Resource Management undated; Smith 2002; Hannan-Jones & Csurhes 2012).

Are there similar species?

Para Grass can be similar to Tanner Grass (Urochloa arrecta), but the latter has single rather than paired spikelets and is not known to be naturalised in Australia.

Why Is It A Weed?

What are its impacts?

Native ecosystems: Outside of pastures, Para Grass invades native wetlands, river margins, and sugar cane plantations. It can have a profound impact on native ecosystems. In some places it can form pure stands, replacing native vegetation (Hannan-Jones & Csurhes 2012). Para Grass can change fuel characteristics in floodplains, when it replaces native grasses. More or more severe fires can in turn further displace native grasses such as Hymenachne acutigluma and damage or kill trees and thus reduce forest cover (Douglas and O’Connor 2004).

When growing along streams, Para Grass can also slow down the water flow, leading to increased sedimentation (Bunn et al. 1998). Terrestrial invertebrates are reduced in abundance and diversity in Para Grass stands compared to stands of the native grass Hymenachne acutigluma (Douglas & O’Connor 2003a). Dense Para Grass stands can also have a detrimental effect on wetland bird populations, but does not appear to impact aquatic invertebrates (Douglas & O’Connor 2003b; G. Blackman, cited in Williams et al. 2005).

How does it spread?

Para Grass can reproduce by seed, but dispersal often happens via broken stem pieces that can root again and grow into a new plant. The stem pieces can be moved by water during floods, but occasionally also by birds (Hannan-Jones & Csurhes 2012).

What is its history in Australia?

Para Grass is native to Africa. It was introduced to Australia in 1884, initially to control riverbank erosion (cited in Douglas & O’Connor 2003b). In the early 20^th century, it was introduced to the northern part of the Northern Territory as a pasture grass (Wesley-Smith 1973). In 1880 it reportedly grew in the Darwin Botanical Garden and was introduced to Arnhem Land in 1922 (Grace et al. 2004). It has since been widely used as a pasture grass in northern Australia, especially on ponded pastures (Hannan-Jones & Csurhes 2012).

How To Manage It?

Best practice management

When controlling Para Grass populations, small and isolated stands should be controlled with higher priority than large infestations. Weed hygiene must be practised to avoid spreading Para Grass from the infested site to other areas.

Non-chemical control: Large Para Grass stands are hard to eradicate, although intensive grazing leads to at least short-term decline in Para Grass cover (Williams et al. 2005). The same is true for grubbing by hand and slashing. Herbicides should best be applied when plants develop inflorescences. However, herbicides should not be used on plants growing over water (Queensland Department of Agriculture, Fisheries and Forestry 2013).

Chemical control: To remove dead material and promote fresh growth that is more susceptible to herbicides, slashing or burning can be performed some time prior to herbicide application. Optimum herbicide treatment time is from December to April (Northern Territory Department of Land Resource Management undated).

Please see the Australian Pesticides and Veterinary Medicines Authority for chemical information http://www.apvma.gov.au

Does it have a biological control agent?

NO

When does it grow? (lifecycle/growth calendar)

Para Grass grows well when the temperature is high enough (above 15 °C) and enough water is available. Flowering times depend on the local climate. In Western Australia, Para Grass has been recorded to flower from April to July (Paczkowska & Chapman 2000) and in the Northern Territory from March to September (Northern Territory Department of Land Resource Management 2012), whereas it grows in summer in northern New South Wales (Jacobs & Wall 1993).

Where Is It Found?

Which states and territories is it found?

NSW, NT, QLD, WA

What areas within states and territories is it found?

Para Grass is naturalised in Queensland and northern New South Wales, in the Northern Territory and in the northern part of Western Australia. The species has also been introduced to other tropical or subtropical parts of the world, where it has naturalised in many places (Hannan-Jones & Csurhes 2012).

Where does it originate?

The native distribution area of Para Grass probably lies in the tropical regions of western and northern Africa (Hannan-Jones & Csurhes 2012).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

NO

Where is it a declared weed?

Not declared in any Australian state or territory.

Government weed strategies and lists – Weeds Australia

Is it on the National Alert List for Environmental Weeds?

NO

Government weed strategies and lists – Weeds Australia

Is it on the Agricultural Sleeper List?

NO

Government weed strategies and lists – Weeds Australia

Names And Taxonomy

Main scientific name

Urochloa mutica

Other scientific names (synonyms)?

• Panicum muticum Forssk.
• Brachiaria mutica (Forssk.) Stapf
• Panicum purpurascens Raddi
• Brachiaria purpurascens (Raddi) Henrard

Does it have other known common name(s)?

Bancroft Grass, Buffalo Grass, California Grass, Dutch Grass, Giant Couch, Giant Panicum, Mauritius Grass, Scotch Grass, Signal Grass, African Wonder Grass