138 ONAGRACEAE 
L. adscendens (L.) Hara 
Perennial rooted aquatic herb with floating 
stems; adventitious roots and white, spongy, 
spindle shaped floats at nodes. Vegetative parts 
glabrous or sparsely hairy with short and long, 
simple, hyaline hairs. Stipules persistent, ovate, 
c. 0.5 mm long. Petioles 3-40 mm long. Leaf 
blades elliptic, oblanceolate, spathulate or obovate, 
11-80 mm long, 4-34 mm wide, L/W 1.8-2.7, 
base attenuate, apex obtuse with dark swollen 
gland on abaxial surface. Flowers in upper axils, 
pubescent on upper part of ovary and calyx. 
Pedicels 6-26 mm long. Bracteoles persistent, 
sub-opposite, c. 1 mm long, inserted about middle 
of ovary. Sepals 5, narrowly triangular, 5-10 mm 
long. Petals white to pale yellow or yellow at 
base, obovate, 8-14 mm long. Stamens 10. Fruit 
brown, cylindrical, obscurely 10-ribbed, 22-27 mm 
long, c. 3 mm wide. Seeds c. 2 mm long, embedded 
in’fruit tissue. Flowering and fruiting: all year 
depending on moisture availability. Fig. 43 
A common species from India to China and 
northern Australia. Common in the DR on lagoons of 
the coastal floodplains. In the terrestrial state on 
drying wetland margins all parts are contracted, 
more densely pubescent and rarely fertile. 
L. hyssopifolia (G.Don) Exell 
Erect annual herb to 0.8 m, rarely taller. Stems 
finely ribbed, often reddish. Glabrous or with sparse, 
minute hairs on stems, underside and margin of leaves, 
ovary and calyx. Stipules persistent, minute. Petioles 
1-6(22) mm long. Leaf blades lanceolate to elliptic, 
10-90 mm long, 1-20 mm wide, L/W 4.2-7.8; base 
attenuate; apex acute. Flowers shortly pedicellate. 
Bracteoles persistent, sub-opposite, inserted about 
middle of ovary, minute. Sepals 4, narrowly triangu- 
lar, c. 3 mm long. Petals yellow, elliptic to obovate, 
1.8-2.5 mm long. Stamens 8. Ovary 4-ribbed, + 
quadrangular. Fruit + sessile, reddish brown, 
cylindrical, 12-24 mm long, c. 1.5 mm wide, 
weathering to 4 persistent ribs. Seeds yellowish 
to pale brown, lenticular, 0.5-0.7 mm long, those 
from basal part of fruit dispersed with persistent 
buoyant structures. Flowering and fruiting: all year 
depending on moisture availability. Fig. 43 
Africa to India, Malesia, Oceania and northern 
Australia. Now considered a pantropic weed. 
Ludwigia 
Common in the DR on coastal floodplains, stream 
margins and moist habitats. 
L. octovalvis (Jacq.) Raven 
Herbaceous, annual or short lived perennial shrub, 
0.4-2 m high. Stems quadrangular, forming 
aerenchymatous tissue at base when in water. 
Vegetative parts, ovary and calyx densely hairy with 
erect hyaline simple and septate hairs, rarely 
subglabrous. Stipules obscure. Petioles 2-8 mm long. 
Leaf blades linear, narrowly elliptic to lanceolate, 
60-165 mm long, 2-35 mm wide, L/W 5-35, base 
attenuate, apex acute to attenuate. Flowers shortly 
pedicellate. Bracteoles persistent, inserted at base of 
ovary, minute or rarely foliaceous. Sepals 4, elliptic 
to lanceolate, 7-13 mm long, falling as fruit matures. 
Petals yellow, obcordate, 6-12(20) mm long. Stamens 
8, anthers hairy or glabrous. Fruit shortly pedicellate, 
brown, + cylindrical, 8-ribbed, 20-55 mm long, 
3-6 mm wide, weathering to 8 persistent ribs. Seeds 
free, brown, + globular, 0.6-0.9 mm diam. Flowering 
and fruiting: Apr - Nov. Fig. 43 
Pantropical; throughout northern Australia and in 
the NT extending into the arid zone. Common in 
the DR in seasonal or perennially moist habitats. 
Worldwide a highly variable species. In the NT a 
distinctive form associated with floodplains differs 
from the typical by being shorter, subglabrous and 
narrowly leaved. 
L. perennis L. 
Annual herb to 1 m, sparsely hairy with minute 
stiff hairs. Stems, leaves and calyx sometimes 
reddish. Stipules obscure. Petioles to 7 mm long. Leaf 
blades narrowly elliptic to linear, 18-110 mm long, 
2-10 mm wide, L/W 11-22; base and apex attenuate. 
Flowers + sessile to shortly pedicellate. Bracteoles 
obscure, at base of pedicel. Sepals 4-5, triangular, 
2-3 mm long. Petals yellow, obovate, 2-4 mm long. 
Stamens 4-5. Fruit + sessile, olivaceous to 
stramineous, + obconic, 4(5)-angled, 6-9 mm long, 
c. 3 mm wide. Seeds free, pink to brown, ellipsoid, 
0.3-0.5 mm long. Flowering and fruiting: Feb - July. 
Fig. 43 
Widespread throughout the Old World and across 
northern Australia. In the NT extending south to 
Newcastle Waters. Common in the DR in seasonal or 
perennially moist habitats. 
