Species

Lysimachia vulgaris

Common Name(s)

yellow loosestrife

Authority

Lysimachia vulgaris L.

Family

Primulaceae

Brief 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.

Flora Category

Vascular - Exotic

Structural Class

Dicotyledonous Herbs other than Composites

Distribution

Scattered distribution, two sites in the Waikato and scattered sites in southern Westland.

Habitat

Wet grassland and the margins of water bodies.

Features

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.

Flowering

December to April

Flower Colours

Yellow

Fruiting

Autumn

Year Naturalised

1940

Origin

Europe, temperate Asia

Reason for Introduction

Ornamental plant

Control Techniques

Not controlled in New Zealand.

Life Cycle and Dispersal

Seed spread by water movement, deliberate planting or garden discards

Attribution

Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA). Features description from Webb et al. (1988).

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.

This page last updated on 21 Aug 2013