Lonicera japonica
NPPA pest plant
Environmental Weed (2024)
Common names
Japanese honeysuckle
Biostatus
Exotic
Category
Vascular
Structural class
Lianes & Related Trailing Plants - Dicotyledons
Flower colours
Red/Pink, White
Detailed description
Vigorous climber, evergreen or semi-evergreen in cold districts. Stems mostly purplish and hirsute when young. Leaves dimorphic - those produced in colder weather in early spring sinuate to deeply lobed; summer leaves and those on reproductive shoots entire. Petiole to 1.3cm long, densely hirsute. Lamina of entire leaves 2.5~12 x 1.5 ~ 6cm, ovate-oblong, ovate or ovate-elliptic, usu. deep shining green or sometimes yellowish-green above, lighter green below, sometimes mottled yellow, densely hairy to glabrous on veins beneath; midrib above glabrous or hairy; base rounded, truncate or subcordate; apex obtuse to acute; leaves subtending; flowers similar but smaller, all free. Flowers in axillary pairs, fragrant; peduncles 5~25mm long, densely hirsute. Bracteoles generally oblong-obovate, much < ovaries. Calyx lobes very small, roughly narrow-triangular, fringed with long hairs. Corolla 2~4.5cm long, usu. white, becoming yellow after antithesis, often flushed pink on reverse, glandular-hairy outside; tube 1~3cm long, cylindric; limb 2-lipped; single linear lobe of lower lip recurving; upper lip 4-toothed. Stamens and style < to = corolla limb. Ovaries separate. Berry 5~7mm diam., broad-ovate to suborbicular, glossy black. Seed around 2mm diam. (- Webb et. al., 1988)
Similar taxa
The plant is a vigorous perennial climber with aromatic flowers (Webb et. al. 1988). The plant has hairy purplish young stems. The flowers are paired and tubular and are white to yellow in colour. The berries are black. The leaves are entire, roughly oval in outline to deeply lobed, lighter green below. Leaves are 2.5-12 x 1.5-6cm.
Habitat
Terrestrial. A plant of coastal and lowland communities which grows in moderately fertile sites. The plant grows more vigorously in deeper valley soils (Department of Conservation 1996). Grows best on calcerous soils and moist forest soils; it rarely establishes on excessively drained and drought-prone sandy or stony soils (Williams and Timmins, 1997).
Occurs in scrub, forest margins, shrublands, disturbed or secondary forest, coastal areas, modified lowland forest, wetland margins, inshore islands, roadsides, farm hedges, wasteland, rough pasture, open forest, forest, wetlands, streambanks and around margins and in clearings (Webb et. al. 1988).
Conservation status
Not applicable
Detailed taxonomy
Genus
Family
Ecology
Flowering
September, October, November, December, January, February, March, April, May
Year naturalised
1926
Origin
E Asia
Reason for introduction
Ornamental
Tolerances
The plant is intolerant to shade and resprouts from broken stems or roots due to physical damage or grazing. Seedlings require high light. Frost, wind and drought tolerant and well adapted to low light. Very tolerant to moisture; moderate tolerance to shade e.g. under Kanuka forest. Growth is limited by the death of shoots by frost; many inland areas of the SI are probably too dry; grows on a range of substrates from pH 4.0-7.9; high degree of shade tolerance, at least for vegetative growth. Requires medium soil fertility (Atkinson 1997).
Life cycle and dispersal
Perennial. Leaves are retained over winter and are capable of growing in equable conditions. Seeds require a period of cold temperatures to break dormancy - temperatures of 5-8 degrees Celsius for 60 days. Germination occurs in spring as soon as air temperatures reach above 10 degrees Celsius. Plant populations seem to grow entirely vegetatively as no seedlings have been seen around established plants (Silbery pers. comm.). Seed viability is unknown (Wotherspoon 1996). Birds disperse seed and road machinery.
Wetland plant indicator status rating
Information derived from the revised national wetland plant list prepared to assist councils in delineating and monitoring wetlands (Clarkson et al., 2021 Manaaki Whenua – Landcare Research Contract Report LC3975 for Hawke’s Bay Regional Council). The national plant list categorises plants by the extent to which they are found in wetlands and not ‘drylands’. The indicator status ratings are OBL (obligate wetland), FACW (facultative wetland), FAC (facultative), FACU (facultative upland), and UPL (obligate upland). If you have suggestions for the Wetland Indicator Status Rating, please contact: [Enable JavaScript to view protected content]
FACU: Facultative Upland
Occasionally is a hydrophyte but usually occurs in uplands (non-wetlands).
Other information
Etymology
japonica: Of Japan
National Pest Plant Accord species
This plant is listed in the 2020 National Pest Plant Accord. The National Pest Plant Accord (NPPA) is an agreement to prevent the sale and/or distribution of specified pest plants where either formal or casual horticultural trade is the most significant way of spreading the plant in New Zealand. For up to date information and an electronic copy of the 2020 Pest Plant Accord manual (including plant information and images) visit the MPI website.
Environmental Weed (2024)
This plant is named in a list of 386 environmental weeds in New Zealand 2024 prepared by DOC. 759 candidate species were considered for inclusion on this new comprehensive list of environmental weeds in New Zealand. The species considered were drawn from published lists of weed species, lists of plants that must be reported or managed by law if observed, existing national and regional programmes and agreements for pest management, and species already managed by the Department of Conservation (DOC). Candidate species were then assessed to see if they were fully naturalised and whether they have more than minor impacts in natural ecosystems. Read the full report here.
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.
LONJAP