Condamine couch

Phyla canescens
Herb
Opposite
Simple
White
Green

a long-lived creeping herbaceous plant usually forming a dense mat over the ground surface.

its small leaves (10-70 mm long and 4-25 mm wide) are oppositely arranged and usually have finely toothed margins.

these leaves are somewhat fleshy and greyish-green in colour.

its flowers are borne in small, dense, rounded clusters (5-10 mm across) on stalks emanating from the leaf forks.

individual flowers are tubular (2-2.5 mm across) and whitish, pinkish, lilac or purplish in colour, with yellowish centres.

its small, dry, fruit are enclosed in the old flower parts and split into two 'seeds' (about 2 mm long) when mature.

Common names 
Also known as: lippia, carpet weed, Condamine curse, fog fruit, frog fruit, hairy fogfruit, mat grass, no-mow grass, phyla weed,
Family 
Verbenaceae
Deciduous 
No
Flowering time 
Flowers appear between spring and autumn.
Native/Exotic 
Exotic
Origin 
Native to South America
Notifiable 
No
State declaration 
Nil
Council declaration 
Class R – Reduce populations
Known distribution 

Widely naturalised in south-eastern and eastern Australia (i.e. in southern Queensland, New South Wales, Victoria and south-eastern South Australia). Also occasionally naturalised in other parts of Queensland and in the inland regions of south-western and southern Western Australia.

Habitat 

Predominantly a weed of pastures, grasslands, waterways and roadsides in semi-arid, sub-tropical and warmer temperate environments, but also grown in lawns and gardens.

Habit 

A long-lived (i.e. perennial), creeping (i.e. prostrate) herbaceous plant with stems up to 1 m in length that form a dense mat over the ground surface.

Impact and control methods 

It has a major environmental impact on riverbanks and waterways, and poses a serious threat to protected wetland areas. Lippia rapidly forms dense carpets preventing the growth of other riparian vegetation. This results in soil erosion, which decreases bank stability and degrades the overall health and quality of the waterway. Its thick, woody taproot enables it to rapidly establish and
persist in poorly structured soils common to the riparian areas and floodplains of the Murray–Darling Basin. Lippia will also readily establish on bare ground. It is an aggressive weed and has the ability to out-compete and dominate in pastures, where it can reduce stocking rates by up to 90% and reduce livestock productivity. Lippia also causes problems in cropping situations. 

Stem and leaves 

The much-branched creeping (i.e. prostrate) stems readily produce roots (i.e. adventitious roots) at their joints (i.e. nodes). Young stems (2-3 mm thick) may appear hairless (i.e. glabrous) but are usually covered in tiny close-lying (i.e. appressed) hairs. They are either green in colour or have a reddish or brownish tinge. Older stems turn greyish in colour and can become somewhat woody with age.

The leaves are borne in pairs along the stems and have bluntly toothed (i.e. crenate), or rarely entire, margins. These leaves are somewhat fleshy (i.e. semi-succulent) and are borne on short stalks (i.e. petioles) 1-8 mm long. They are relatively small (10-70 mm long and 4-25 mm wide), greyish-green in colour and either hairless (i.e. glabrous) or covered in minute close-lying (i.e. appressed) hairs.

Flowers and fruits 

The flowers are borne in small, dense, rounded clusters (5-10 mm across) that elongate slightly with age (10-25 mm long). These flower clusters are borne on stalks (i.e. peduncles) 1-11 cm long emanating from the leaf forks (i.e. axils). Individual flowers are tubular in shape (2-2.5 mm across) with five inconspicuous lobes and are whitish, pinkish, lilac or purplish in colour, with yellowish centres. The inner flower buds are darker in colour than the open flowers. Flowering occurs throughout most of the year, and is particularly apparent when soil moisture is most favourable.

Reproduction and dispersal 

This species reproduces vegetatively via stem fragments as well as by seed.

Stem fragments and seeds are spread during floods and by other soil disturbances. Dispersal of this species has also been aided by its use as a low-maintenance lawn in some areas.

Similar species 

Lippia (Phyla canescens) is very similar to carpet weed (Phyla nodiflora). These two species are very difficult to distinguish, except by the different habitats they are usually found in:

lippia (Phyla canescens) is found mostly in wetter inland habitats on clay soils. Its leaves are usually greyish-green with very short teeth and its flowers are usually lilac or pinkish in colour.

carpet weed (Phyla nodiflora) is found mostly in more humid coastal areas on sandy soils. Its leaves are usually dark green with obvious teeth and its flowers are usually whitish in colour.