Acacia 
MIMOSACEAE 
Trees, shrubs, lianes or rarely herbs, often prickly or spiny. Leaves alternate, whorled or rarely 
opposite, 1-pinnate, bipinnate, modified into phyllodes or absent, commonly with a swollen, basal 
pulvinus. Stipules mostly present, sometimes developed into prickles or spines. Flowers in spikes, 
racemes, heads or compound inflorescences. Calyx of (3)5(6) sepals, free or united, sometimes reduced 
or absent. Corolla of (3)5(6) petals, free or joined below to form a tube. Stamens 4-10 or numerous, 
free or connate below, commonly coloured and long exserted. Carpels 1 or rarely several and free. 
Fruit a legume, usually dry and dehiscent along both sutures, sometimes indehiscent or breaking 
transversely into 1-seeded joints. Seeds often with an elongate funicle or funicular aril. 
About 60 genera and 3000 species worldwide. Widespread in tropical and subtropical regions, especially in 
arid or semi-arid climates. About 17 genera in Australia; represented in the NT by 11 genera, 9 of which occur 
in the DR. [Verdcourt, 1979; Nielsen, 1992] 
1. Leaves reduced to simple entire phyllodes ..........c.esessessssessessssssessssesssscsssseseessseeseseseeneeeenes Acacia 
[Wee Leaves bipinnatemamenternrrtcertrtenttcrnitictre ricer tie ert 2, 
2 meee VOOCY Lianemnmirctssrtrrccertirrrtsssterstt emertcen st terete tt rertitricccrcrtrenertcrssrsn Entada 
2: Herbs, shrubs or trees 3 
seh Leaflets >7 mm wide 4 
3. Leaflets <7 mm wide 6 
4. VeafletstalternateBunmrniinrmsrsmirecesst itt titer eeceemiestireristerisrsrte Adenanthera 
4 Wem Leatlets Opposite Merrcrrssstetiren Tiree Mitticiri rerereitrsert terrier ecetettersterertTretrreets 5 
5. Pods thin, dehiscent, pale brown; leaflets dull, pale to mid green Albizia 
SF Pods woody, indehiscent, black; leaflets shiny, dark green ........sesssssssssssssssseseesessessseeseseenes Cathormion 
6. Flowers pink to purple; fruit breaking into 1-seeded articles . Mimosa 
6. Flowers yellow to white; fruit a dehiscent pod ........cscsssssecsseceseesesesesteeneeceeseeeecseseaeesaneese 7 
th Leaves sensitive; sprawling to erect shrubs to 2 M High .......eesssesssssssseseseseseseseeststeeeeenees 8 
7s Leaves not sensitive; shrubs to trees >2 M High .........sessssseeseseseseeesesssencecestseeeeeeeessenshenseeee 9 
Same Podsi>Oimmiwide-t<9 seeds per pod mereesetttttccetttseetartrretretsrittsntiteisestistrisrtte Neptunia 
Si embods<jimm iwide;!>8 Seeds per pod Prrsvsnitesreerstiarececrstsceteestesbrevetstcastoncrttiesvheesetessteettes Desmanthus 
OMMeulnflorescencesa'spiketinrrrttryiresciteseititraessererentretecrreereetinriseserttiresteresserttiestrsevrttses sete; Acacia 
9. Inflorescence a globular head ........ssssssssssssssecsssssssssessseesssssnssnnsssesseessssssassssssesssssanieeesssecee 10 
10. Pods with thin valves, 14-21-seeded; seeds <8 mm long, without funicles «0.0.0... Leucaena 
10. Pods woody, mostly <14-seeded; seeds >9 mm long, with funicles ............ccscesssesesseseees Acacia 
ACACIA Mill. 
Trees or shrubs, sometimes spiny. Leaves bipinnate, modified into phyllodes or rarely absent; glands often 
present. Flowers hermaphrodite or male and hermaphrodite in spicate or globular heads. Calyx usually 
4-5-lobed. Corolla 4-5-lobed. Stamens numerous, mostly free. Pods variable, flat to cylindrical, straight, curved, 
coiled or twisted, dehiscent or indehiscent. Seeds typically with a well developed aril. 
A large genus of c. 1200 species in the tropics and subtropics of both hemispheres. About 147 described 
species in the NT with many more undescribed taxa. About 30 species in the DR. The genus produces 
