Acacia 
A. humifusa Cunn. ex Benth. 
Spreading shrub, 0.3-2 m high. Branchlets terete, 
densely tomentose, hairs erect, hyaline. Stipules 
persistent, white, triangular, 2 mm long, pubescent. 
Pulvinus 3-10 mm long, hairy. Phyllodes straight, 
dimidiate, broadest towards base, 25-76 mm long, 
15-52 mm wide, L/W 1.2-2.3, densely tomentose, 
hairs erect, hyaline, primary veins 3(4), concurrent 
with lower margin near base, secondary veins 
oblique or penniveined, reticulate, base asymmetri- 
cal or oblique, apex acute to obtuse, mucro straight. 
Glands prominent, 1, at pulvinus. Inflorescences on 
simple axillary peduncles, 1-2 per axil. Spikes 
yellow, 10-70 mm long, 5-6 mm wide, with flowers 
dense to interrupted; peduncle 0-13 mm_ long, 
hairy, rachis hairy. Pods sessile, brown, linear to 
oblong, slightly curved, raised over seeds, 15-75 mm 
long, 3.5-4.5 mm wide, coriaceous, hairy, nerves 
obscure, obtuse. Seeds longitudinal in pod, black, 
oblong to cylindrical, 6.5 mm long, 3 mm wide. 
Flowering: throughout the year; fruiting: Mar - July. 
Fig. 5 
Widespread across northern Australia from the 
Kimberley to Cape York. Scattered localities in DR 
on skeletal or lateritic soils, typically on sandstone 
plateaux and scree slopes. 
A. latescens Benth. 
Erect tree, 4-9 m high. Bark brown, fissured. 
Branchlets slightly angular and ribbed, glabrous. 
Stipules caducous. Pulvinus 3-5 mm long, glabrous. 
Phyllodes curved, linear to narrowly oblanceolate, 
80-260 mm long, 4-18 mm wide, L/W 7.3-60, 
glabrous, primary veins 2, rarely 1 or 3, secondary 
veins oblique or penniveined, reticulate, base 
attenuate, apex acute. Glands 3, scattered along 
dorsal margin and at pulvinus. Inflorescences 
extended axillary racemes or panicles, 4-11 heads 
per raceme, axis length 10-30 mm long. Heads 
globular, white to cream, 4-6 mm wide; peduncle 
5-16 mm long, glabrous. Pods stipitate, greyish, 
linear to oblong or rarely slightly constricted between 
seeds, straight, raised over seeds and slightly domed, 
50-210 mm long, 1 1-20 mm wide, coriaceous, smooth, 
glabrous, transversely reticulately nerved, margin 
thickened slightly, acute. Seeds oblique in pod, dark 
brown to black, flattened ellipsoid, 9-10 mim long, 
5-7 mm wide. Flowering: Apr - July; fruiting: Aug - 
Jan. Fig. 5 - 
An NT endemic; common in eucalypt woodland 
across the Top End. Common in the DR. Forms with 
very narrow phyllodes commonly occur on sandstone 
substrates. 
MIMOSACEAE | 13 
A. leptocarpa Cunn. ex Benth. 
Tree, 5-15 m high. Bark brown to grey, fissured. 
Branchlets angular, glabrous. Stipules persistent, 
reddish, narrow-triangular, 0.9 mm long, glabrous. 
Pulvinus 4-6 mm long, glabrous. Phyllodes curved, 
narrowly elliptic, 115-175(270) mm long, 7-27(55) 
mm wide, L/W (4.5)7.2-17.2, glabrous, primary veins 
3(4), secondary veins parallel and widely spaced, 
sparsely anastomosing, base attenuate, apex acute, 
mucro straight. Glands inconspicuous, 1, near base. 
Inflorescences on simple axillary peduncles, mostly 2 
per axil. Spikes yellow, 30-63 mm long, 4-6 mm 
wide, loosely flowered; peduncle 3-10 mm long, 
glabrous, rachis glabrous. Pods stipitate, brown with 
pale margins, linear to oblong, curved to weakly 
coiled, raised over seeds, 115-150 mm long, 3.5-4 
mm wide, coriaceous, glabrous, nerves obscure or 
absent, margin thickened, acute. Seeds longitudinal in 
pod, black, flattened oblong, 3.5-5 mm long, 2-3 mm 
wide. Flowering: May - Oct; fruiting: Sept - Nov. 
Fig. 5 
Top End to Cape York and coastal southern Qld; 
also New Guinea. Uncommon in the DR where known 
from Melville Is. and the Elizabeth R. Coastal 
localities.on sandy soils. 
*A, mangium Willd. 
Tree, 10 m high. Bark grey. Branchlets angular 
and ribbed, glabrous. Stipules caducous, brown, 
triangular, 1 mm long, glabrous. Pulvinus 4-8 mm 
long, glabrous, winged on lower margin. Phyllodes 
straight, dimidiate, broadest at middle, 115-185 mm 
long, 23-64 mm wide, L/W 3.7-5, punctulate, 
glabrous, main longitudinal nerves 4, basally 
confluent but distant from lower margin, distant, 
anastomoses numerous in a longitudinally elongated 
reticulum, base oblique, apex acute, mucro straight, 
blunt and knob-like. Glands 1, 0-3 mm above 
pulvinus, broadly swollen around circular orifice. 
Inflorescences racemose, 2-3 heads per raceme, 
raceme axis | mm long. Spikes pale yellow, 96 mm 
long, 6 mm wide, flowers interrupted; peduncle 
10 mm long, hairy, rachis hairy. Pods sessile, brown, 
linear to oblong, coiled, flat, c. 120 mm long, 5 mm 
wide, coriaceous, glabrous, nerves obscure or absent, 
acute. Seeds not seen. Flowering: Jan; fruiting: old 
fruits without seed in Jan. Fig. 6 
Cultivated in the DR; native to north Qld and New 
Guinea and now widely cultivated in plantations for 
timber. 
A. mimula Pedley 
Erect tree, to 7m high. Bark dark grey, fissured 
