White Ball Acacia

Acaciella glauca syn. Acacia angustissima syn. Acacia boliviana Syn. Mimosa glauca
Tree
Alternate
Compound
White
Cream
Green

A shrub or small tree with younger stems that are somewhat reddish in colour. Its twice-compound leaves are fernlike in appearance and have several pairs of branchlets. Its small white fluffy flowers are borne in globular or slightly elongated clusters fruit form flattened, elongated, pods (4-7cm long) that turn brown when mature. This species (or series of closely related subspecies) can be highly variable.

This Plant is Prohibited Matter under the Biosecurity Act 2014 and Must be Reported to Biosecurity Queensland Immediately 

Common names 
Also known as: redwood, wild dividivi,
Family 
Fabaceae:
Deciduous 
No
Flowering time 
Flowering and fruiting in January to February.
Native/Exotic 
Exotic
Origin 
Native to the Caribbean and north-eastern South America.
Notifiable 
Yes
State declaration 
Category 1
Council declaration 
As per State Declaration
Known distribution 

Occasionally naturalised in northern and central Queensland, particularly around Ingham. The distribution of this species in Australia is relatively unknown, although the Queensland Herbarium has 11 naturalised records from the area. One of these is from the Cook pastoral district, nine are from the North Kennedy pastoral district and one is from the South Kennedy pastoral district. This tree was discovered and removed from a yard in Graceville

Habitat 

This species has since been found in a variety of habitats in northern Queensland, from the wet tropics to semi-arid environments, and on a variety of soil types. 

Habit 

A large shrub or small tree usually growing 1.5-6 m tall.

Redwood (Acaciella glauca) is regarded as an environmental weed in northern Queensland and as a potential environmental weed in other parts of Queensland. After being introduced into Australia for evaluation as a potential woody forage legume, it probably escaped from sites where it was trialled for this purpose.

This species has since been found in a variety of habitats in northern Queensland, from the wet tropics to semi-arid environments, and on a variety of soil types. It is thought to pose a significant threat to rangeland biodiversity in northern Australia and several new populations have been recorded in recent years (e.g. a large thicket about 15 km south of Ingham).

Redwood (Acaciella glauca) was recently listed as a priority environmental weed in the Far North Queensland Natural Resource Management region. It is also regarded as being invasive on Mauke, in the Cook Islands , where it is said to form dense thickets.

Stem and leaves 

The stems are smooth in texture, sparsely hairy (i.e. puberulent) or almost hairless (i.e. glabrate), and do not have any spines. They are often reddish-brown in colour, particularly when young.

The twice-compound (i.e. bipinnate) leaves are finely divided and and fern-like in appearance. These leaves (4.5-13 cm long) are alternatively arranged along the stems and are borne on stalks (i.e. petioles) 2-5.5 cm long. Each leaf has 3-9 pairs of branchlets (i.e. pinnae) 3-6 cm long, and each of these leaf branches has 10-30 pairs of small leaflets (i.e. pinnules). These leaflets are generally somewhat oblong in shape (3.5-8 mm long and 1.8-2.4 mm wide) with rounded tips (i.e. obtuse apices). They are almost hairless (i.e. sub-glabrous) or slightly hairy (i.e. slightly pubescent) and have paler undersides (i.e. they are discolorous).

Flowers and fruits 

The white or cream-coloured flowers are borne in small dense clusters, with 3-5 of these clusters arranged in each of the upper leaf forks (i.e. axils). The clusters are rounded or slightly elongated in shape (i.e. globular or ellipsoid) and are borne on stalks (i.e. peduncles) 12-20 mm long. Each cluster contains numerous (15-30) small flowers that are borne on a very short stalk (i.e. pedicel) 0.6-1 mm long. The small flowers have five inconspicuous sepals (0.6-0.8 mm long), five tiny petals (2.5-3 mm long) and numerous (100 or more) prominent stamens (5-5.5 mm long) that give the flowers a very fluffy appearance.

The fruit is a relatively large, oblong, and flattened pod (4-7 cm long and 10-15 mm wide). They are hairless (i.e. glabrous) and turn from green to dark brown as they mature. Each pod contains 5-8 dark brown seeds, which are are oval (i.e. ellipsoid) or somewhat rounded (i.e. globular) in shape (3-5 mm long and about 3 mm wide).

Reproduction and dispersal 

This species reproduces by seed. The seeds may be eaten by cattle, other large animals, or birds and then spread after passing through their digestive systems intact. They may possibly also be spread by water or on vehicles.