Quick Facts

Quick facts

• Thatching Reed (Thamnochortus insignis) is a native of South Africa.
• It is a reed like plant forming tall tussocks up to 2.5 m high.
• It is dispersed by winged nutlets that are blown in the wind.
• If introduced to Australia, it has the potential to become a serious invasive weed.
• It should not be introduced by the horticultural industry as an ornamental.

What Does It Look Like?

What is it?

Thatching Reed (Thamnochortus insignis) is a tall, evergreen, grass-, rush-, sedge- or reed-like tufted perennial herb that grows up to 2.5 m high and has short rhizomes (underground stems). It forms tussocks that are 0.5–1 m across at the base and spread up to 3 m or more in diameter at the top and consist of a mass of upright, green, leafless aerial stems (culms) that are unbranched, stout, smooth and hairless. Sheaths (reduced leaves) occur along the culms and are persistent and frayed in their top half.

Male and female flowers are borne on separate plants. Brown to golden inflorescences (flower-heads) occur at the top of unbranched flowering culms. The male inflorescences are pendulous, occurring as small tassels that sway in the wind, while female inflorescences (flowering structures) are more erect. The inconspicuous flowers are very small, brown, at least as wide as long and hidden by bracts (modified leaves) in the flower heads.

The fruit is a tiny brown nutlet with attached segments that act as wings (Linder 1985; Ithaka Harbors Inc. 1995; Haaksma & Linder 2000; Jamieson 2001).

Like many of the reeds, this species will be difficult to identify beyond the level of genus or even family. For further information and assistance with identification of Thatching Reed, contact the herbarium in your state or territory.

Flower colour

Brown

Growth form (weed type/habit)

Herb

Where it currently grows? Preferred habitat

In its natural habitat, Thatching Reed, like many reeds, is an important component of the heathland vegetation or fynbos of southern Africa (in winter rainfall regions of the Cape Province), growing on limestone hills or sandy flats in coastal regions (Haaksma & Linder 2000). It also occurs along roadsides where seed has been distributed by trucks carrying thatching material (Jamieson 2001).

Are there similar species?

Thatching Reed may easily be confused with other reeds, including native species of Restionaceae, e.g., species of Leptocarpus, Meeboldina, Lepyrodia and Baloskion (previously included in Restio). To the untrained eye and even those more experienced in botany, restiads can also be confused with sedges (family Cyperaceae) and sometimes grasses (family Poaceae) or rushes (family Juncaceae). Unlike sedges, rushes and grasses, restiads usually have nodes (points where leaves arise) along their stems that bear leaf sheaths only or abscission rings where the sheaths have dropped off.

Due to the difficulty in identifying reeds and sedges (Kodela 2008 pers. comm.), if you suspect you have found this weed please seek assistance from the herbarium in your state or territory.

Why Is It A Weed?

What are its impacts?

As the name Thatching Reed suggests, this species is used in the Cape Province of South Africa as a thatching reed (roofing material) because of its long stems. It has spread in the region by seed being distributed in the transport of the thatch (Linder 1985, 1990; Haaksma & Linder 2000; Jamieson 2001).

Native ecosystems: The tall reed-like tussocks of Thatching Reed can form dense stands that could compete with native vegetation and reduce biodiversity. It has spread effectively in South Africa (Linder 2006 pers. comm.).

How does it spread?

Thatching Reed reproduces by seed. The nutlets containing the seed are winged to aid dispersal by wind (Haaksma & Linder 2000). Seeds have been spread by the distribution of thatching material by vehicles in South Africa (Haaksma & Linder 2000; Jamieson 2001).

What is its history in Australia?

Thatching Reed is advertised outside its natural distribution as an attractive ornamental plant for horticulture. It was grown in a commercial nursery in Western Australia for a short time in about 2005 (Briggs 2008 pers. comm.).

How To Manage It?

Best practice management

Although advertised as an attractive, drought tolerant ornamental for gardens (San Marcos Growers undated), Thatching Reed could escape from cultivation and become a serious weed, especially in coastal areas with similar winter rainfall patterns to the Cape Province of South Africa where it naturally occurs. Plants should not be traded in the horticultural industry (Kodela 2008 pers. comm.).

Non-chemical control: Control measures in Western Australia, where Thatching Reed is a declared plant, include prohibiting the introduction, growing and movement of plants or seed including transport via contaminated machinery, livestock or fodder and the eradication of any infestations (Western Australian Department of Agriculture and Food undated).

Individual plants or small infestations can be dug out, taking care to remove all of the main roots and preventing seed dispersal (seed heads should be cut off first and placed in sealed bags).

Chemical control: For larger infestations, approved chemical controls could be investigated (Kodela 2008 pers. comm.).

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)

In South Africa, seed germination of Thatching Reed occurs directly after the onset of the winter rains, allowing the seedlings several months to establish themselves before the harsher summer conditions. It takes several years for plants to develop into adult form and produce inflorescences that set seed. Flowering occurs in summer and plants produce large amounts of seed in autumn. Adult plants may live for over ten years (Haaksma & Linder 2000; Jamieson 2001).

Where Is It Found?

Which states and territories is it found?

Not naturalised in any Australian state or territory.

What areas within states and territories is it found?

Thatching Reed is not known to be naturalised in Australia. It has the potential to become an invasive weed, particularly in south-western Western Australia where environmental conditions are similar to those of its natural distribution in the Cape Province of South Africa (Briggs 2008 pers. comm.).

Where does it originate?

Thatching Reed is native to South Africa (Linder 1985).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

NO

Where is it a declared weed?

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

Thamnochortus insignis

Other scientific names (synonyms)?

Does it have other known common name(s)?

Albertinia Thatching Reed, Dekriet (South Africa)