Acanthus mollis
Environmental Weed (2024)
Common names
bear’s breeches
Biostatus
Exotic
Category
Vascular
Structural class
Herbs - Dicotyledons other than Composites
Flower colours
Red/Pink, White
Detailed description
Perennial herb to about 120 cm, with thick roots. Petiole usually 10-50 cm on leaves arising from the root crown, much shorter (2-5 cm) on leaves arising from vertical stem. Leaves variable, but usually dark green and with several lobes. White flowers with pink, purple or brownish veins are produced on the central tall spike, these mature first at the bottom of the spike. Seeds are produced in individual capsules 3-4 cm long.
Similar taxa
Easily distinguished by the large divided leaves and the distinctive flower head.
Habitat
Usually found near old settlements, in partial shade and along riverbanks.
Conservation status
Not applicable
Detailed taxonomy
Family
Acanthaceae
Ecology
Flowering
October, November, December, January, February, March, April
Fruiting
November, December, January, February, March, April, May
Year naturalised
1958
Origin
S.W. Europe
Reason for introduction
Ornamental
Tolerances
Can tolerate moderate shade, but flowers best in at least partial light.
Life cycle and dispersal
Primarily escapes from cultivation by vegetative spread, although seed is viable. Dispersed by gravity, water and birds. Root fragments grow easily and once established this plant can be hard to eliminate from a site.
Other information
Etymology
acanthus: From the Greek ákantha ‘thorn’
mollis: Soft
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.
ACAMOL