Red sesbania

Sesbania punicea
Tree
Opposite
Compound
Red
Green

red sesbania is a deciduous shrub or tree with many slender branches. It is a poisonous plant that forms dense infestations along waterways. Red sesbania is a serious weed in South Africa, and has also been reported in Lesotho and Zimbabwe.

Red sesbania has not yet been found in Queensland. It has the potential to become a serious pest if introduced and planted in gardens here.

Red sesbania is a prohibited invasive plant under the Biosecurity Act 2014.

Common names 
Also known as: black acacia, Brazil rattlebox, Brazilian glory pea, false poinciana, purple sesbane, purple sesbania, rattle box, rattlebush, red seine bean,
Family 
Fabaceae
Deciduous 
Yes
Flowering time 
Late Spring to Autumn
Native/Exotic 
Exotic
Origin 
Native to South America
Notifiable 
Yes
State declaration 
Category 1
Council declaration 
As per State Declaration
Known distribution 

Red sesbania has not yet been found in Queensland. It has the potential to become a serious pest if introduced and planted in gardens here.

Habitat 

S. punicea is predominantly associated with areas where soil moisture levels are consistently high. Seedlings are especially vulnerable to desiccation when soil moisture levels decline.

Habit 

Sesbania punicea is a deciduous shrub or small tree up to 5 m high with many slender, thornless branches. The bark is smooth and green on young growth, turning reddish and then brown with age. 

Sesbania punicea is capable of forming dense impenetrable thickets which can prevent river access, exclude native species and alter habitats. S. punicea can increase hydraulic roughness, thus raising the stage during flood events and potentially causing water bodies to burst their banks as well as increase the rates of lateral erosion. S. punicea is also known to contain saponine which is toxic to humans and other vertebrate species.

Stem and leaves 

The leaves are dark green above and somewhat paler below, drooping, 100-200 mm long and pinnate. The leaflets are oblong, ending in tiny pointed tips.

Flowers and fruits 

The flowers are red or orange in colour, approximately 20 mm long and produce showy, dense sprays up to 250 mm long that droop or project outwards. Flowering is predominantly in spring and early summer. The fruits are brown pods that have four characteristic longitudinal wings. They are oblong in shape, 60-80 mm long by 10 mm wide with distal tips that are sharply pointed. Each pod contains up to 10 seeds (each approximately 6 mm long) born in cavities separated by cross partitions

Reproduction and dispersal 

Seeds of S. punicea are hard-coated but they have no inherent dormancy and germinate as soon as imbibition occurs. S. punicea has high moisture requirements, especially for seed germination and seedling survival, so the plants only become naturalised in areas where soils remain moist for relatively long periods. In regions with predominantly summer rainfall, S. punicea plants are sometimes found in open areas away from water but most occur in the vicinity of rivers and streamsoisture is available