Quick Facts

Quick facts

• Sacciolepis interrupta is a perennial semi-aquatic grass.
• It is native to temperate and tropical Asia but does not occur in Australia.
• It has been targeted as a potential environmental weed by the Northern Australia Quarantine Service. This is due to its proliferation in similar habitats which are close in proximity to the northern coastline of Australia.
• In Asia, it provides fodder for buffalo and cattle, is a common weed of rice fields, reducing productivity and is a host for disease-carrying mosquitoes.

What Does It Look Like?

What is it?

Sacciolepis interrupta is a perennial (long lived) semi-aquatic grass. It has creeping or floating, hollow, swollen, spongy, yellow or purple culms (stems), which are trailing, 2 m long and 1 cm thick. Roots are produced from the nodes (joint of a stem) when wholly or partially submerged in water. The flowering culm is upright, growing to 1 m in height. The leaf sheath (part of the leaf encasing the stem) is swollen and purple, growing to 5–6 cm long. The ligule (the structure between the sheath and the leaf blade) is membranous, thin and up to 3 mm long. The leaf blade is flaccid and thin, growing to 30 cm long and 15 mm wide (Dassanayake et al. 1994; Gilliland et al. 1971).

The flower head is situated at the end of the culm and is slender, compact and spike like, 10-30 cm long, with numerous short 5–6-flowered branches. The shortly stalked spikelet (flowering structure) is about 3.5 mm long, slightly sac-shaped, with 1 upper fertile floret (small flower) and a lower sterile floret that is white in appearance when in fruit (Sharp and Simon 2002). The glumes (modified leaves below the spikelets) are unequal, the upper one about 3.4 mm long, the lower 1.2 mm (Gilliland et al. 1971). Old spikelets fall early giving the flower head an interrupted appearance i.e. with gaps (Waterhouse & Mitchell 1998).

The mature fruit is a grain about 2 mm long, elliptic and compressed (Soerjani et al. 1987).

For further information and assistance with identification of Sacciolepis interrupta, contact the herbarium in your state or territory.

Flower colour

White

Growth form (weed type/habit)

Grass

Where it currently grows? Preferred habitat

Sacciolepis interrupta is semi-aquatic, growing abundantly in water or in seasonally inundated sites, at low and medium elevations (Lazarides 1980; Dassanayake et al. 1994). In Sri Lanka, it occurs in rice fields, marshes and shallow lakes (Dassanayake et al. 1994). In Indonesia, it grows in swamps or stagnant water, in pools, along ditches and drains, and it is a weed of rice fields, irrigation channels and wetlands (Soerjani et al. 1987; Waterhouse & Mitchell 1998).

Are there similar species?

Sacciolepis interrupta may be distinguished from S. indica and S. myosuroides by its swollen spongy creeping stems and its creeping rather than upright habit (Gilliland et al. 1971). S.indica and S. myosuroides are native to Australia and Asia (Sharp & Simon 2002).

In its native habitat, it often found mixed with Hymenachne acutigluma from which it may be distinguished by its hollow stem, short inflorescence and branches, and long upper glume (modified leaf below the spikelet) (Soerjani et al. 1987). H. acutigluma is a native of India and South East Asia, also occurring along the coast of the Northern Territory and northern Queensland (AVH 2008; Gilliland et al. 1971).

Sacciolepis interrupta extends into eastern Africa where it resembles S. africana except for its larger pointed spikelets. However, the division between the two species is not clear-cut, and there is some overlap in individual characters (Burkhill 1985; Clayton 1989).

Why Is It A Weed?

What are its impacts?

Sacciolepis interrupta has been targeted as a potential environmental weed by the Northern Australia Quarantine Service. This is due to its proliferation in habitats that are similar, and close in proximity, to northern Australia (Waterhouse & Mitchell 1998).

Agriculture: The spongy culms of Sacciolepis interrupta provide succulent fodder for buffalo and cattle (Lazarides 1980). The grain of S. interrupta is known to be collected and used as a food source in central Chad (Freedman 1998) and possibly in Nigeria, although it is unclear whether the grain used here is S. interrupta or S. africana (Burkhill 1985).

S. interrupta is a common weed of rice-fields in Indonesia and Assam in India (Islam et al. 2004; Soerjani et al. 1987) and it is a major weed of transplanted lowland rice. With no control at all, weeds may reduce rice yields by 15–40% (Islam et al. 2004). In Indonesia, S. interrupta is a weed of deep water rice. These rice fields are under 60–120 cm of water for 6–7 months of the year (Soerjani et al. 1987).

Human impact: In India, S. interrupta growing in rice fields and fallow areas has been shown to be a host plant for the breeding of the three species of the mosquito Mansonia, which provide a vector for the round worm, Brugia malayi (Krishnamoorthy et al. 2007). This parasite causes serious disease in humans (Filarial Biology and Pathology undated).

How does it spread?

The seed and rooting stem fragments of Sacciolepis interrupta are dispersed by water (Soerjani et al. 1987; Waterhouse & Mitchell 1998).

What is its history in Australia?

Sacciolepis interrupta does not occur in Australia (AVH 2008; Waterhouse & Mitchell 1998).

How To Manage It?

Best practice management

Non-chemical control: In Indonesia and Assam, manual weeding using simple tools such as rotary weeders is the most common method of controlling the growth and spread of Sacciolepis interrupta (Islam et al. 2004; Soerjani 1987).

Does it have a biological control agent?

NO

When does it grow? (lifecycle/growth calendar)

Sacciolepis interrupta is a perennial plant.

Where Is It Found?

Which states and territories is it found?

Not naturalised in any state or territory.

What areas within states and territories is it found?

Sacciolepis interrupta does not occur in Australia (AVH 2008; Waterhouse & Mitchell 1998).

Where does it originate?

Sacciolepis interrupta is native to temperate and tropical Asia, in particular, China, India, Sri Lanka, Burma (Myanmar), Malaysia, Nepal and Indonesia (Waterhouse & Mitchell 1998; GRIN 2008) and occurs in, but is probably not native to, Africa, especially Tanzania, Botswana, Zambia and Zimbabwe (Burkhill 1985; Clayton 1989).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

NO

Where is it a declared weed?

NT, WA

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

Sacciolepis interrupta

Other scientific names (synonyms)?

• Hymenachne interrupta (Willd.) Büse
• Panicum indicum Hack.
• Panicum interruptum Willd.
• Panicum inundatum Kunth
• Panicum turritum Thunb.
• Panicum uliginosum Roth ex Roem. & Schult.

Does it have other known common name(s)?