Tropaeolum majus
Environmental Weed (2024)
Common names
nasturtium
Biostatus
Exotic
Category
Vascular
Structural class
Herbs - Dicotyledons other than Composites
Flower colours
Red/Pink, Yellow
Detailed description
Scrambling or trailing, hairless, aromatic, annual or short-lived perennial, occ climbing to 2 m high. Stems succulent, to 10 m long, sap watery. Leaves distinctive, roundish shield-shaped, often slightly asymmetric, bluish below, up to 18-21 cm diam, with long stalk attached to back of leaf. Flowers solitary or 2-3 clustered, tubular, 4 cm diam, 5 irregular petals, scarlet orange or yellow, Oct- May. Seed capsule 3-sided, green, 10-14 mm long, succulent. Seeds caper-like.
Similar taxa
No species is easily confused with T. majus in NZ. Cultivated plants have many different flower colours.
Habitat
Terrestrial. Disturbed sites, especially adjacent to gardens and dumps. Shrubland, herbfield, wetland, streamsides.
Conservation status
Not applicable
Detailed taxonomy
Family
Ecology
Flowering
(January), October, November, December, January, February, March, April, May (December)
Year naturalised
1883
Origin
N. Andes
Reason for introduction
Ornamental
Tolerances
Tolerates salt, wind, hot to cold, semi-shade, damp, physical damage, poor soils.
Life cycle and dispersal
Perennial. Reproduces primarily via vegetative spread and fragmentation but seeds are also produced. Dispersal is through garden dumping and clonal spread and birds may disperse seeds.
Other information
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.
TROMAJ