Harrisia Cactus - Eriocereus martinii, Syn Harrisia martinii Family: CACTACEAE
Harrisia Cactus is an aggressive weed species that can form dense,
It is highly competitive, with an extensive system of surface feeding,
and underground storage, roots. If left unmanaged, harrisia cactus
quickly out competes desirable plant species.
The spiny nature of the plant means that stock find infested pastures
less favourable and mustering in and around infestations is difficult.
The stems of harrisia cactus tend to form a tangled sprawling mess,
sending down roots when they come in contact with the ground.
The underground storage root contains many dormant buds,
allowing rapid regrowth should the above ground section of the
plant be damaged.
Up to 125,000 tubers per hectare have been reported in dense
In addition to vegetative spread, harrisia cactus produces large
numbers of bright red succulent fruit that contain as many as 1000 Above: Harrisia Cactus, also known as Moonlight Cactus, reproduces by fruit and by stem
sections which readily take root when in contact with the ground
seeds. These fruit are particularly attractive to birds, which consume
and disperse the seeds.
Seeds readily geminate if sufficient moisture is available. Laboratory Description
tests have successfully germinated seed after five years. Seedlings Harrisia Cactus is a sprawling perennial
quickly form a tuberous storage root, enabling them to persist under cactus species that forms tangled
unfavourable environmental conditions. infestations about half a metre in
Harrisia cactus has a preference for, but is not restricted to, brigalow
and associated softwood scrubs. The shade and shelter provided by Stems may reach several metres in
these scrubs provide ideal growing conditions and allow infestations length. They are approximately 4cm in
to flourish. diameter with 4-6 ribs running along
their length. Stems are covered in
Harrisia cactus is a Class 2 declared plant in Queensland. It is illegal
numerous spines up to 3.5cm in
to grow or sell harrisia cactus and landholders must try to keep their
land free of this species.
Flowers open at night. They are pink
to white. Flowering occurs during Above: Emerging Harrisia Cactus
Fruit is red and spiny with succulent white flesh containing
hundreds of black seeds.
Vegetative reproduction is via stems that send
down roots when they come in contact with
Dispersal is primarily via birds that consume
the fruit and seeds. Mammals, including feral
Harrisia cactus fruits (above) and seeds prolifically. pigs may also consume the fruit and aid in
Stock tend to avoid infested pastures due to the sharp dispersal.
Community Information Sheet No 20 Produced by South West NRM Ltd
Author: Nathan Kirby, Geodorum Consulting Updated: April 2007
Controlling Harrisia Cactus is a Priority.
If left untreated, Harrisia cactus has the potential to infest large
areas of south west Queensland reducing agricultural productivity
and causing environmental damage. Currently only isolated
infestations are known to exist at Charleville and near Mitchell.
South West NRM Ltd has identified Harrisia cactus as a priority weed
species in the region and is working with landholders and local and
state governments to locate and control infestations.
Report suspected sightings of Harrisia cactus to your local council Above: Harrisia Cactus forms tangled infestations. Stems sprawl across the ground, sending
pest officer or to South West NRM Ltd. down roots when in contact with the soil.
As with any weed, preventing spread and early treatment of any new or small infestations, is the most cost effective method of control. Once
established harrisia cactus is difficult to eradicate and expensive to control.
Small infestations can be controlled by physically digging out and burning plants. Take care to remove all plant material, particularly the
tubers. Foliar application of registered herbicides provides effective control, but can be costly to apply over large areas. Information on
specific herbicides and application rates can be found in the Department of Natural Resources and Water Pest Fact PP22 - Harrisia cactus,
Moonlight Cactus - Eriocereus martini and Eriscereus tortuosus.
Two biological control insects have been successfully released and exert some level of control. The mealy bug Hypogeococcus festerianus has
been the most effective agent, particularly on dense infestations. Manual introduction and dispersal of mealy bugs may be required to assist
in establishment, especially in lightly infested areas.
Harrisia Cactus Distribution,
South West NRM Ltd Region, 2006
Density & Distribution
Abundant & Widespread
Abundant & Localised
Common & Widespread
Common & Localised
Occasional & Widespread
Occasional & Localised
Map based on 2006 Annual Pest Distribution
Survey Data supplied by Department of
Natural Resources and Water. Compiled on
approx 17 * 17km grid squares. For further
details visit http://www.dpi.qld.gov.au
References and further reading.
Department of Natural Resources and Water, Land Protection, 2006, Pest Fact PP22 -
Harrisia cactus, Moonlight Cactus - Eriocereus martini and Eriscereus tortuosus.
Parson, W and Cuthbertson, E, 1992, Noxious Weeds of Australia