16 MIMOSACEAE 
triangular or linear or narrowly elliptic, 6-24 mm 
long, 1-3 mm wide, L/W 3.3-11, resinous or hoary 
with minute stellate crystals, coriaceous to rigid, 
glabrous, primary veins obscure but surface longitu- 
dinally striate, secondary veins obscure, sparsely 
anastomosing, base attenuate and oblique, apex 
asymmetric. Glands 1, near base. Inflorescences on 
simple axillary peduncles. Heads globular, pale 
yellow, 4-7 mm wide; peduncle 7-15 mm long, 
resinous, glabrous. Pods sessile, olivaceous, 
broadest towards apex and tapered to base, 
straight, flat, opening elastically from apex, 
22-67 mm long, 3-5 mm wide, woody, resinous, 
glabrous, obliquely reticulately nerved, margin 
thickened slightly, hooked. Seeds oblique in pod, 
brown, flattened oblong, 4.5-5 mm long, 1.7-2.2 mm 
wide. Flowering: Feb - Dec; fruiting: Feb - August. 
Fig. 7 
Across northern Australia north of 18° S in a 
variety of habitats. Rare in the DR where known only 
from Litchfield NP on sandstone. 
A. oligoneura F.Muell. 
Open shrub, 1-1.5 m high, thin stems arising 
from woody rootstock after fire. Branchlets terete 
or slightly ribbed, resinous with resin scattered 
and scurfy in appearance, glabrous. Stipules 
caducous. Pulvinus 1.5-3 mm long, glabrous. 
Phyllodes straight or slightly curved, narrowly 
oblanceolate, 110-137(190) mm long, 12.5-20 mm 
wide, L/W 7.3-10.8, sparsely resinous as branchlets, 
glabrous, main longitudinal nerves 3, distant, 
anastomoses numerous forming a longitudinally 
elongated reticulum, base attenuate, apex obtuse, 
mucro short and knob-like, oblique or straight or 
obscure. Glands |, first gland 0-4 mm above pulvinus. 
Inflorescences on simple axillary peduncles, 1-3 per 
axil, or terminal panicles. Spikes yellow, 18-30 mm 
long, 4.5-6.5 mm wide, densely to loosely flowered; 
peduncle 5.5-8 mm long, resinous, glabrous, rachis 
resinous, glabrous. Pods sessile, brown, broadest 
towards apex and tapered to base, straight, flat, 
opening elastically from apex, 78-82 mm long, 
5-7.5 mm wide, woody, resinous but dull and scurfy, 
glabrous, obliquely reticulately nerved, hooked or 
acute. Seeds oblique in pod, brown, narrowly 
ellipsoid or oblong, 5-5.5 mm long, 2-2.5 mm wide. 
Flowering: Jan - May; fruiting: Dec. Fig. 8 
From the DR to the VRD and Kimberley; 
uncommon in the DR where recorded from 
Noonamah to Litchfield and the Daly River area. A 
poorly known species only recently recognised in 
the DR. Open woodland on rocky slopes. 
Acacia 
Acacia oligoneura 
Fig. 8 
A. oncinocarpa Benth. 
Spreading shrub or tree, 1.5-4 m high. Bark grey, 
fissured. Branchlets slightly angular, blotchy with 
reddish patches of resin, glabrous. Stipules 
persistent, white, narrow-triangular, 1 mm long, 
glabrous. Pulvinus 2-3 mm long, glabrous. Phyllodes 
straight or curved, narrowly elliptic to elliptic, 
58-110 mm long, (4)7-29 mm wide, L/W 3-9.3(20), 
glabrous, primary veins 3 but sometimes obscure, 
secondary veins parallel and widely spaced, 
anastomoses absent or very sparsely anastomosing, 
base attenuate, apex acute to obtuse, mucro straight 
or hooked. Glands 1, at pulvinus. Inflorescences on 
simple axillary peduncles, 1-4 per axil. Spikes pale 
yellow, 33-80 mm long, 3-6 mm wide, loosely 
flowered; peduncle 2-7 mm long, slightly resinous, 
glabrous, rachis slightly resinous, glabrous. Pods 
sessile, yellowish to brown, broadest towards apex 
and tapered to base or linear to oblong, straight, flat, 
opening elastically from apex, 55-110 mm long, 
4.5-10 mm wide, woody, scurfy resinous, glabrous, 
obliquely reticulately nerved, margin thickened, 
hooked. Seeds oblique in pod, brown, oblong to 
ellipsoid, 4-6 mm long, 2-3.5 mm wide. Flowering: 
Mar - Aug, but around Darwin usually in May; 
fruiting: July - Oct. Fig. 7 
