96 FABACEAE 
Pycnospora 
PYCNOSPORA Wight & Arn. 
One species in the tropics and subtropics of the Old World, widespread across northern Australia. 
Taxonomically close to Desmodium, differing mainly by the pod. 
P. lutescens (Poir.) Schindler 
Erect or spreading perennial shrub with annual 
stems. Stems sparsely to densely hairy with simple 
white hairs. Stipules persistent, striate, attenuate, 6- . 
10 mm long. Leaves pinnately 3-foliolate, 1-foliolate 
at base of plant, rachis to basal leaflets 5-15 mm, 9- 
20 mm overall; stipels persistent, filiform; leaflets 
dorsiventral, oblanceolate or obovate, (11)15-45 mm 
long, 6-25 mm wide, L/W 1.3-2.5(3); venation 
prominent below with 3° veins + scalariform; thinly 
hairy with simple and minute hooked hairs; base 
rounded, apex obtuse to emarginate; terminal leaflet 
usually larger than basals. Inflorescence racemose, 
mostly terminal and unbranched to 150 mm long, 
densely hairy (including calyx) with simple, yellow 
glandular based and hooked hairs. Bracts caducous, 
ovate, acuminate, striate, 6-7 mm long. Pedicels 2-4 
mm long. Calyx 3-4 mm long; lobes 4, attenuate, 
2/3-3/4 of total length, upper bifid. Corolla lilac, 
glabrous; standard not clawed, not reflexed, obovate, 
c.6 mm long, without auricles; wings and keel clawed. 
Stamens 9+1, filaments alternately long and short; 
anthers uniform, fixed near base, versatile. Ovary 
hirsute, ovules c. 9; style incurved, glabrous, stigma 
capitate. Pod black when mature, dehiscent, 
coriaceous, oblong, inflated, 8-10 mm long, 4-5 mm 
wide, thinly hairy with patent simple, minute hooked 
and rarely glandular based hairs, venation prominent, 
transverse, reticulate. Seeds dark mottled, oblong, c. 
4mm long, 2 mm wide. Flowering: Jan - Apr; fruiting: 
Jan - June. Fig. 28 
In Eucalypt savanna on lateritic, sandy, skeletal and 
rarely clay soils. 
RHYNCHOSIA Lour. 
Slender twining or prostrate vines with annual stems and perennial roots. Variously pubescent with simple 
and glandular based hairs; vesicular glands present on vegetative parts, especially leaf undersurface, calyx 
and back of standard. Stipules persistent; stipels setaceous, c. 1 mm long. Leaves pinnately 3-foliolate, leaflets 
discolorous with 2 prominent basal nerves, basal leaflets asymmetric. Inflorescence an axillary raceme with 
reflexed flowers well spaced on the upper half of the rachis; bracts caducous; bracteoles absent. Calyx 5- 
lobed, acuminate, unequal, the upper 2 fused. Corolla yellow or yellow with red or brown lines; standard 
orbicular or almost so, reflexed, auriculate, lacking calli, with vesicular glands and minute hairs on back 
especially towards the apex. Stamens 9+1, anthers uniform. Ovary 2-ovuled; style incurved above; stigma 
small, terminal. Pod falcate, flattened, 2-valved, dehiscent, slightly raised over the seeds, base attenuate, apex 
obtuse. Seeds longitudinal in pod, often mottled, subreniform, flattened; funicle decurrent on the inside margin 
of the pod; hilum lateral; caruncle minute. 
A pantropical genus of c. 150 species. Four species occur in Australia with 2 in the NT and DR. 
1. Terminal leaflet acuminate; basal leaflets 1.3-1.8 times as long as Wide ..........c.cccceseseeeee 
1. Terminal leaflet obtuse; basal leaflets 0.9-1.1 times as long as Wide ...........esesteeseseeseeees 
R. australis Benth. 
All parts glabrate except for the tomentose pedicel, 
calyx and fruit. Reddish vesicular glands mostly 
confined to the leaf undersurface, calyx and back of 
standard. Stipules narrowly triangular, 2-4 mm long. 
Leaf rachis to basal leaflets 12-42 mm, 20-55 mm 
overall; /eaflets dark green, thin, ovate, base rounded, 
apex acuminate; basal leaflets 20-53 mm long, 11-34 
R. australis 
R. minima 
mm wide, L/W 1.3-1.8; terminal leaflet 20-55 mm 
long, 15-45 mm wide, L/W 1-1.6. Inflorescence to 
160 mm long; bracts narrowly triangular, c. 1.5 mm 
long. Pedicels c. 1 mm long. Calyx 4-6 mm long. 
Corolla yellow sometimes with maroon stripes; 
standard 6-8 mm long. Pod dark brown, c. 20 mm 
long, 5-6 mm wide, tomentose with short white hairs 
interspersed with long glandular based hairs, often 
