Species

Lythrum hyssopifolia

Common Name(s)

hyssop loosestrife

Authority

Lythrum hyssopifolia L.

Family

Lythraceae

Brief Description

Low growing, many branched herb with narrow leaves, either in pairs or individual up to 2.5 cm long, and small (4 mm across) pink flowers produced directly from the stem next to the upper leaves.

Flora Category

Vascular - Exotic

NVS Species Code

LYTHYS

The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.

Structural Class

Dicotyledonous Herbs other than Composites

Distribution

Common throughout both islands as far south as Otago

Habitat

Wet disturbed places such as roadside gravel and exposed margins of water bodies.

Features

Glabrous annual with diffuse or dense habit; stems to c. 40 cm tall, ± quadrangular, often pinkish, sometimes producing roots towards the base. Lvs sessile or subsessile, (6)-8-25 × (1.5)-2-8 mm, usually linear or narrow-linear, sometimes linear-oblong on lower part of main stem and on young plants, entire; base rounded to subcordate; apex acute or obtuse. Fls solitary in lf axils, monomorphic. Pedicels < 1.5 mm long; bracteoles > pedicels. Calyx 3-5.5 mm long; tube narrow-obconic and tapering gradually to narrow base, ribbed; lobes 1-1.5 mm long, narrow-triangular to linear-subulate; epicalyx segments 0.5-0.8 mm long, broad-triangular. Petals 6, 2.5-4 mm long, pink, crumpled; claw short; limb elliptic-obovate. Stamens (3)-4-7-(10), included; filaments generally of different lengths. Style 1-2.5 mm long. Capsule 4-6 mm long, cylindric, included in calyx tube. Seed 0.7-1 mm long, ovoid, slightly asymmetric.

Similar Taxa

Similar to rose loosestrife (Lythrum junceum), but all parts of that plant are larger.

Flowering

Summer

Flower Colours

Red / Pink

Fruiting

Autumn

Year Naturalised

1855

Origin

Europe, western Asia and North Africa

Reason for Introduction

Unknown, seed or soil contaminant

Control Techniques

Not controlled in New Zealand.

Life Cycle and Dispersal

Seed dispersed by water, animals or contaminated machinery.

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.

Popay et al (2010).  An illustrated guide to common weeds of New Zealand, third edition.  NZ Plant Protection Society Inc, 416pp.

Johnson PN, Brooke PA (1989).  Wetland plants in New Zealand.   DSIR Field Guide, DSIR Publishing, Wellington. 319pp.

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