Harrisia cactus: declared pest

Page last updated: Saturday, 28 September 2019 - 12:15pm

Please note: This content may be out of date and is currently under review.

Harrisia cactus (Harrisia martinii) is a declared pest in Western Australia (WA). This article describes the nature of the plant with links to requirements land owners/occupiers must adhere to and pest control methods.

Form: shrub — perennial

Status: not present in WA


A spiny rope-like night flowering cactus, forming tangled mats 30-60 centimetres high, reproducing both vegetatively and by seed.

Stems: Bright green, fleshy 2.5-4 centimetres diameter, ribbed lengthwise, with each rib having pyramid-like humps 5-7.5 centimetres apart. At the top of each is a tuft of grey felted hairs, with one to three sharp central spines 10-35 millimetres long and some five to seven radial spines one to six millimetres long.

Leaves: Inconspicuous, at base of spines.

Flowers: White, large, funnel shaped with petals fusing into a slender green tube 15-20 centimetres long.  Flowers open for one night and wither in the early morning.

Fruit: Red, almost spherical four to five centimetres diameter with several wart like protuberances topped by cushions of felted hairs and spines similar to those on the stem. When ripe the fruit splits down one side. It contains some 400 to 600 seeds embedded in white pulp.

Seeds: Black, small and almost spherical.

Agricultural and economic impact

An environmental weed. Dense infestations in pastoral areas can interfere with livestock feeding and farming operations such as mustering.

Declared pest category

The Western Australian Organism List (WAOL) contains information on the area(s) in which this pest is declared and the control and keeping categories to which it has been assigned in Western Australia (WA). Search for Harrisia cactus in the WAOL using the scientific name Harrisia martinii.

Requirements for land owners/occupiers and other persons

Requirements for land owners/occupiers and other persons if this pest is found can be sourced through the declared plant requirements link.

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MyPestGuide™ Reporter
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Pest and Disease Information Service (PaDIS)
+61 (0)8 9368 3080

Control method

Control methods for this declared plant can be found through the Harrisia cactus control link.

Contact information

Pest and Disease Information Service (PaDIS)
+61 (0)8 9368 3080
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