mouse-ear chickweed

Cerastium glomeratum
infestation growing in a mown area (Photo: Sheldon Navie)
habit (Photo: Sheldon Navie)
habit with mostly upright stems (Photo: Sheldon Navie)
habit with spreading stems (Photo: Sheldon Navie)
close-up of stems, showing insects trapped by their sticky hairs (Photo: Sheldon Navie)
close-up of the hairy paired leaves (Photo: Sheldon Navie)
densely clustered flowers (Photo: Sheldon Navie)
close-up of flowers, with hairy sepals and five two-lobed petals (Photo: Sheldon Navie)
immature and mature fruit (Photo: Sheldon Navie)
close-up of mature fruit with ten small teeth at the tip (Photo: Sheldon Navie)
seedling (Photo: Sheldon Navie)
Herb
Opposite
Simple
White
Green

A short-lived herbaceous plant with upright or spreading stems usually growing 5-20 cm tall. Its soft stems and leaves are covered in hairs, some of which are sticky. Its relatively small leaves (5-32 mm long) are paired along the stems. Its small white flowers have five petals with deeply notched tips, and may appear to be ten petals at first glance. Its small fruit (5-10 mm long) have ten teeth at their tips.

Common names 
Also known as: mouse-ear chickweed, cerastium, clammy chickweed, clustered mouse ear, common mouse-ear chickweed, mouse ear chickweed, mouse-eared chickweed, sticky chickweed, sticky mouse-ear,
Family 
Caryophyllaceae
Deciduous 
No
Flowering time 
Winter - Spring
Native/Exotic 
Exotic
Origin 
Native to northern Africa, Europe and western Asia.
Notifiable 
No
Council declaration 
SIL – Special Investigation List
Known distribution 

Naturalised throughout south-eastern Queensland, but primarily found in the Moreton district. Also occasionally naturalised in the coastal districts of central Queensland. This species is widely naturalised in the wetter parts of southern and eastern Australia (i.e. in New South Wales, the ACT, Victoria, Tasmania, South Australia and south-western Western Australia). It is also naturalised on Lord Howe Island, Norfolk Island, and in the southern parts of the Northern Territory.

Habitat 

A weed of lawns, gardens, footpaths, pastures, disturbed sites, waste areas and crops. It prefers damp shady sites.

Habit 

A short-lived (i.e. annual) herbaceous plant with upright (i.e. erect or ascending) or spreading (i.e. decumbent) stems. It usually grows 5-20 cm tall, but occasionally reaches up to 45 cm in height.

Impact and control methods 
Stem and leaves 

The soft stems and leaves are covered in hairs, some of which are sticky (i.e. glandular). The relatively small leaves (5-32 mm long and 3-15 mm wide) are simple and paired along the stems. The lower leaves are borne on stalks (i.e. petioles) up to 12 mm long, while the upper leaves are smaller and almost stalkless (i.e. sessile or sub-sessile). These leaves are generally oval (i.e. elliptic) or egg-shaped in outline (i.e. obovate) with entire margins and rounded or shortly-pointed tips (i.e. obtuse or apiculate apex). Both surfaces are covered in long spreading hairs (i.e. villous), while the margins are also hairy (i.e. ciliate).

Flowers and fruits 

The flowers are grouped into dense clusters (i.e. cymes) at the tips of the stems, with each flower being borne on a short stalk (i.e. pedicel) 1-7 mm long. These flowers have five white petals (2.5-5 mm long) with deeply notched tips, and may appear to be ten petals at first glance. They also have five green sepals (4-5.5 mm long) that are narrow (i.e. lanceolate) and hairy (i.e. pilose). Each flower also has ten stamens and an ovary topped with five small styles. Flowering occurs mostly during winter and spring. The fruit are small cylindrical capsules (5-10 mm long and 1.3-2 mm wide), each with ten small teeth at their tip. They turn from green to pale brown or whitish in colour as they mature. Each capsule contains several pale brown seeds (0.5-0.6 mm across) with slightly rough surfaces (i.e. they are finely tuberculate).

Reproduction and dispersal 

This species reproduces only by seed. These seeds are spread by wind, water, vehicles, in mud and in contaminated agricultural produce.

Similar species 

Mouse-ear chickweed (Cerastium glomeratum) can be confused with chickweed (Stellaria media), lesser chickweed (Stellaria pallida) and tropical chickweed (Drymaria cordata subsp. cordata). These species can be distinguished from each other by the following differences: mouse-ear chickweed (Cerastium glomeratum) has very hairy stems and relatively large hairy leaves (5-32 mm long). Its flowers have five white petals that are deeply lobed, and may appear to be ten petals at first glance chickweed (Stellaria media) has a line of hairs along one side of its stems and relatively large hairless leaves (5-25 mm long). Its flowers have five white petals that are deeply lobed, and may appear to be ten petals at first glance lesser chickweed (Stellaria pallida) has a line of hairs along one side of its stems and relatively small hairless leaves (less than 7 mm long). Its flowers do not have any petals tropical chickweed (Drymaria cordata subsp. cordata) has hairless stems and relatively small hairless leaves (6-12 mm long). Its flowers have five white petals that are deeply lobed, and may appear to be ten petals at first glance.