Sedge, Cyperus

Quick Facts

Cyperus teneristolon is an introduced, slender, perennial sedge with distinctive dark red to purplish-black dense flower heads.
It produces plentiful seed and has extensive underground stolons and root system.
It is potentially a weed (like Mullumbimby couch) of lawns, flower beds and horticultural crops as well as moist disturbed sites in native bushland.
Control along the creekline near Katoomba may limit its spread.

What Does It Look Like?

What is it?

Cyperus teneristolon is a slender perennial sedge with delicate creeping stolons (ground covering stems) that root at the nodes and persist underground. Sedges are evergreen plants with triangular stems that generally grow in damp areas. The flowering stems (culms) are triangular in cross-section, smooth, to 50 cm high, and about 1 mm in diameter. Leaves are flat, to 45 cm high and about 1 mm wide.

The flower head is more or less cylindrical to egg-shaped, very dark red to purplish-black, made up of one to several dense clusters of tiny flowers ('spikelets'), with 3–5 leafy bracts longer than the flower head and spreading or bent downwards. The spikelets are flattened, numerous, 3–5 mm long, and contain 2–4 flowers.

The fruit (a nut) is dry, contains one seed and does not split open to release the seed when on the plant (description from Haines & Lye (1983); Gordon-Gray (1995); CRC (2003) and Wilson (2004)).

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

There is no well-established common name for this species in Australia. The name 'Cyperus' has been suggested but that is not practical because many species belong to that genus, including some weedy species. It has been decided to refer to the species here by its scientific name to prevent confusion (CRC 2003).

Flower colour

Red, Green

Growth form (weed type/habit)

Herb

Where it currently grows? Preferred habitat

The only known colonies of C. teneristolon grow in sandy, disturbed ground beside a small creek in the Blue Mountains. In its native regions in eastern Africa, it is found in often dampish, open grassland or associated with rocky outcrops, often disturbed habitats (Haines & Lye 1983; Gordon-Gray 1995).

Are there similar species?

Cyperus teneristolon is vegetatively similar to Mullumbimby Couch (C. brevifolius) in being a slender plant with extensive stolons. It differs from Mullumbimby Couch in its distinctive very dark red to purplish-black cylindrical to egg-shaped flower heads (Wilson 2007, pers. comm.).

Why Is It A Weed?

What are its impacts?

Cyperus teneristolon is on the Alert List for Environmental Weeds, a list of 28 non-native plants that threaten biodiversity and cause other environmental damage. Although only in the early stages of establishment, these weeds have the potential to seriously degrade Australia's ecosystems.

Agriculture: Cyperus teneristolon is a weed of vegetable crops in higher altitude areas of Kenya (Terry & Michieka 1987) and is also in disturbed grazing lands in those areas (Muasya 2000, pers. comm.). As it is a weed in overseas agricultural areas with climatic and environmental conditions similar to those that occur in Australia, it is seen as a potential threat to Australia's environment and agricultural productivity (CRC 2003).

Native ecosystems: Its potential to invade native ecosystems is not known. However, C. teneristolon has been observed breaking through special weed proof matting in a revegetation area alongside a creek line, suggesting the plant may potentially be an aggressive invader (CRC 2003). In New South Wales, it is colonising disturbed areas along a creek line near Katoomba (CRC 2003; Sainty & Associates 2004). It may continue to threaten native ecosystems downstream if not managed (CRC 2003).

How does it spread?

The main dispersal of C. teneristolon is likely to be by seed but it can spread over relatively short distances very effectively by its creeping stolons that root at the nodes (Wilson 2007, pers. comm.). The stolons spread the plant by clambering across the ground and forming new populations nearby. Rhizomes sprout new growth similarly, producing detached clumps. It is also possible for the stolons and rhizomes to break off and propagate in downstream locations, making the risk of spread even greater (CRC 2003).

What is its history in Australia?

Cyperus teneristolon was first recorded in February 2000 near Katoomba, where it was found growing near and through jute matting laid down for revegetation between a picnic area and the creek. It was subsequently found upstream near a rubbish tip, so seed could have been transported down the creek, or it may have been a contaminant in the matting, but that is considered unlikely (Wilson 2007, pers. comm.).

How To Manage It?

Best practice management

Chemical control: In Kenya, Cyperus teneristolon has been successfully controlled by herbicides, but none is registered to control it in Australia. Any new outbreaks should be reported immediately to your state or territory weed management agency or local council. Do not try to control it without their expert assistance. Control effort that is poorly performed or not followed up can actually help spread a weed and worsen the problem (CRC 2003).

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

Does it have a biological control agent?

When does it grow? (lifecycle/growth calendar)

Not much is known about the life cycle of C. teneristolon in Australia. The following information was obtained from its overseas locations, and from casual observations made in its current habitat in the Blue Mountains. Because C. teneristolon is a sedge, and from a tropical region, it does not go dormant during the winter, but slows its growth in cool periods. It regrows and germinates during the spring months and flowers in the summer (CRC 2003).

Where Is It Found?

Which states and territories is it found?

NSW

What areas within states and territories is it found?

So far, Cyperus teneristolon is only naturalised near Katoomba, along one creek line (CRC 2003; Sainty et al. 2004).

Cyperus teneristolon is potentially a weed (like Mullumbimby couch) of lawns, flower beds and horticultural crops, as well as disturbed areas in seasonally moist native bushland from south-eastern Queensland to Victoria and possibly on the Atherton Tableland and other elevated tropical areas. It is less likely to be found in the Mediterranean climates of South Australia and Western Australia.

Where does it originate?

Cyperus teneristolon is native to eastern Africa from Ethiopia to southern Africa (Richardson et al. 2006). However, the comment by Haines & Lye (1983) that it is often in disturbed habitats, suggests that it is probably introduced in parts of eastern Africa and its natural range is smaller. In tropical eastern Africa, it is only found at higher altitudes.

In part of its native range (Natal, South Africa), it is becoming rare 'probably due to interference with its natural habitats' of open, dampish places in grasslands and around rock outcrops (Gordon-Gray 1995).