Lysimachia vulgaris
Common names
Yellow loosestrife
Biostatus
Exotic
Category
Vascular
Structural class
Herbs - Dicotyledons other than Composites
Simplified description
Tall (up to 1 m) plant with paired (or 3 or 4’s) willow-like leaves up the more-or-less upright stems, groups of 10 or more yellow flowers, 1.5 cm across.
Flower colours
Yellow
Detailed description
Summergreen herb; stems erect, ± minutely glandular-hairy, to c. 1 m tall, arising from underground rhizomes. Lvs opposite, shortly petiolate to subsessile. Lamina 4-11 × 1.5-4 cm, lanceolate to ovate or elliptic, glabrous above, minutely glandular-hairy beneath and dotted with black glands, entire; base cuneate to rounded; apex acute. Panicle terminal, many-flowered, glandular-puberulent, with leaflike bracts subtending lower branches; upper bracts subulate to lanceolate. Pedicels often > fls. Calyx 4-5 mm long; lobes lanceolate, acuminate, rounded at base, glandular-ciliate and dark-margined. Corolla limb c. 2 cm diam., yellow, often with pinkish flush towards base, dotted with minute glands; lobes 7-10 mm long, ± elliptic-oblong. Stamens 3-5 mm long; filaments united to c. ⅓ length, densely glandular-scaly. Style > stamens, glabrous. Capsule 3-4.5 mm diam., ± globose. Seed broad-ellipsoid, flattened with thick rounded margin.
Similar taxa
Non-flowering plants are similar to purple loosestrife (Lythrum salicaria) but in yellow loosestrife the upper surface and edges of the leaves are dotted with black or orange glands.
Distribution
Scattered distribution, two sites in the Waikato and scattered sites in southern Westland.
Habitat
Wet grassland and the margins of water bodies.
Conservation status
Not applicable
Detailed taxonomy
Family
Primulaceae
Ecology
Flowering
December to April
Fruiting
Autumn
Year naturalised
1940
Origin
Europe, temperate Asia
Reason for introduction
Ornamental plant
Control techniques
Not controlled in New Zealand.
Life cycle
Seed spread by water movement, deliberate planting or garden discards
Other information
Referencing and citations
References and further reading
Webb, C.J.; Sykes, W.R.; Garnock-Jones, P.J. (1988). Flora of New Zealand Volume 4: Naturalised pteridophytes, gymnosperms, dicotyledons. Botany Division, DSIR, Christchurch.
Clapham, A.R.; Tutin, T.G.; Warburg, E.F. (1962). Flora of the British Isles. Cambridge University Press, Second Edition. 1269pp.
Attribution
Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA). Features description from Webb et al. (1988).
Some of this factsheet information is derived from Flora of New Zealand Online and is used under a Creative Commons Attribution 3.0 New Zealand licence.