pg . 30
NQ DRY TROPICS WEED FREE
GIANT SENSITIVE PLANT
Mimosa invisa
GIANT SENSITIVE PLANT
SHRUBS
DESCRIPTION
This is a shrubby or sprawling annual that can behave as a perennial .
Stems are bunching , 4 angled and often scrambling over other plants . The angles usually have a line of sharp , hooked prickles .
Leaves are arranged on alternate areas of the stem . They are bright green and feathery , with each leaf divided into 5 to 7 pairs of segments . Each segment carries about 20 pairs of very small leaflets which close up when disturbed , injured , or at nightfall .
Flowers are very small pale pink , round , fluffy balls about 12 millimetres across , on short stalks in the leaf joints . Numerous pods are clustered , each about 25 millimetres long and 6 millimetres broad when ripe . Clothed with small prickles , these later break into 4 or 5 one seeded pieces . It flowers from April to the end of June .
Habitat in horticultural and grazing areas
Weed characteristics will choke out cane , other crops and grassland , causing loss of crop and pasture production .
Dispersal seeds have been known to lie dormant for up to 50 years .
BIOSECURITY MATTER
Restricted . This species is Category 3 Restricted matter under Queensland Legislation .
HOW TO ACT
Slashing is effective in controlling seedlings and small shrubs . Foliar spraying is effective at controlling and reducing populations . An introduced biological control called GSP psyllid ( Heteropsylla spinulosa ) is also available . Fire can be used to stimulate the seed bank for further control .