Opuntia monacantha
Environmental Weed (2024)
Common names
drooping prickly pear
Biostatus
Exotic
Conservation status
Not applicable
Category
Vascular
Structural class
Trees & Shrubs - Dicotyledons
Flower colours
Yellow
Detailed description
Large cactus to about 4 m high, often with thick cylindric trunk, and drooping habit on larger plants. Each stem segment grows to about 30 cm long, is flattened, egg-shaped (can be elongated), and attached at the pointy end. One or two spines emerging from holes in the segments. Yellow flowers up to 9 cm diameter with red tinges are produced on the margins of the stem segments. Fruit up to 7.5 x 3.5 cm, fleshy and reddish purple.
Similar taxa
At least 2 other large Opuntia appear to be naturalised in New Zealand. O. monocantha can be distinguished from O. ficus-indica as it never has more than 2 spines per cluster, and stems are green. O. ficus indica has 1-6 spines per cluster, and is blue-green. O. robusta is also sparingly naturalised, this species has massive circular segments up to 40 cm diameter.
Habitat
Terrestrial. Sandy beaches and coastal places.
Detailed taxonomy
Genus
Family
Ecology
Flowering
February, March, April, May
Year naturalised
1855
Origin
S. Brazil, Argentina
Reason for introduction
Ornamental
Tolerances
Very tolerant of salty coastal sites.
Life cycle and dispersal
Reproduces by vegetative spread and seed. Many seed produced; dispersed by humans, birds and soil movement.
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.
OPUMON