Ludwigia repens
Common name
Red luwigia
Family
Onagraceae
Flora category
Vascular – Exotic
Structural class
Herbs - Dicotyledons other than Composites
Conservation status
Not applicable
Brief description
A wetland or aquatic, and sometimes submerged perennial species. The slender stems are often reddish when submerged, and may be creeping, floating or prostrate and rooting at the nodes. The flowers have four yellow petals and are stalkless at the base of leaf pairs. Leaves are glossy, oval and occur in opposite pairs.
Distribution
Only known from one site at Western Springs, Auckland, but a common plant in the aquarium trade.
Habitat
Still and slow flowing shallow water bodies
Detailed description
up to 3 cm long. branched stems ascending or floating procumbent, rooting freely at the nodes. Glossy broadly lanceolate-elliptic to suborbicular leaves opposite, usually green above and purplish below, up to 4.5 cm long and 2.5 cm wide, base tapering into a petiole 5–25 mm long. Flowers axillary, paired, sepals 4, triangular. Petals 4, yellow, 1–3 mm long. Stamens 4. Fruit oblong, corners rounded to barely angled, 5–7 mm long, c. 2.5 mm wide
Similar taxa
Ludwigia palustris is very similar with opposite leaves and creeping habit, but can be distinguished by the green flowers lacking petals Ludwigia peploides subsp. montevidensis and alligator weed (Alternanthera philoxeroides). Alligator weed also has opposite leaves, and L. peploides subsp montevidensis has yellow flowers and alternate leaves.
Flowering
January to April
Flower colours
Yellow
Life cycle
Unknown whether seed is produced in NZ, spread by stem fragmentation
Year naturalised
2008
Origin
Native of southern USA, Mexico and the Carribean.
Reason for introduction
Ornamental aquarium and pond plant.
Control techniques
Not controlled in New Zealand.
Etymology
repens: From Latin repere meaning to creep, means creeping
Attribution
Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA).
References and further reading
New South Wales Flora Online (http://plantnet.rbgsyd.nsw.gov.au/)