Lythrum hyssopifolia
Common name
hyssop loosestrife
Family
Lythraceae
Flora category
Vascular – Exotic
Structural class
Herbs - Dicotyledons other than Composites
NVS code
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.
LYTHYS
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.
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
Life cycle
Seed dispersed by water, animals or contaminated machinery.
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.
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.