Gymnocoronis spilanthoides
NPPA pest plant
Environmental Weed (2024)
Common names
Senegal tea
Biostatus
Exotic
Conservation status
Not applicable
Category
Vascular
Structural class
Herbs - Dicotyledonous composites
Simplified description
Sprawling emergent perennial herb, becoming upright when flowering. Leaves are dark green, opposite, and ovate to lanceolate in shape. They vary in size from 5 to 20 cm long, 2.5 to 5 cm wide, and are on shortish stalks. Leaf margins are serrate and slightly wavy. Flowers are whitish, numerous and highly scented.
Flower colours
White
Detailed description
Perennial aquatic herb to 1+ m high. Roots finely fibrous, also aerially from stem nodes. Stems erect at first, becoming prostrate, branching and rooting at nodes, 1-1.5 m long, 5-10 mm diam at first, to 20 mm with age, hollow, inflated, floating. Leaves paired with opposite stalks joined at stem, 50-200 x 25-50 mm, lance-shaped, dark green, serrate, slightly wavy. Flowerhead clover-like, with many thin white florets, Nov-Apr. Seed yellow-brown, 5 mm diam. Plant dormant over Winter, dies back to rootstock if chilled, resprouts in Spring.
Similar taxa
Is similar to Alternanthera philoxeroides (alligator weed) when in its sprawling phase but can be differentiated from alligator weed by its narrower leaves with serrated margins and reddish tinge. G. spilanthoides also has clusters of flowers.
Habitat
Aquatic: Emergent. The plant grows in wet marshy soils and at water margins, Plant grows in wetland communities in still or flowing water.
Detailed taxonomy
Genus
Family
Endemic family
No
Ecology
Flowering
December, January, February, March, April, May.
Fruiting
summer/autumn
Year naturalised
1991
Origin
South America.
Reason for introduction
Ornamental aquarium and pond plant. Was sold in the aquarium trade as costata.
Tolerances
The plant is tolerant to shade, frost and poor drainage and intolerant to drought.
Control techniques
Notify regional council if found
Life cycle and dispersal
Perennial. Plants are dormant in winter, producing shoots in spring from protected buds in the nodes and crown. Reproduces sexually by seed. Vegetative reproduction occurs through the production of roots at stem nodes and vegetative fragmentation.
Seed stems and root fragments are dispersed in water, on livestock hooves and machinery. Can also be spread by dumped aquaria contents when liberating fish.
Other information
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.
GYMSPI
Referencing and citations
References and further reading
Champion et al (2012). Freshwater Pests of New Zealand. NIWA publication. http://www.niwa.co.nz/freshwater-and-estuaries/management-tools/identification-guides-and-fact-sheets/freshwater-pest-species.
Attribution
Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA).