Prickly paddy melon fruit and flower © Sarah Sun

Prickly paddy melon

Cucumis myriocarpus

Quick facts

Status
Permitted s11
Life Cycle
Annual
Growth Form
Herb
Origin
Southern Africa
Flowers
Yellow
Dispersal
Birds, other animals

Names

Other Common Names: Gooseberry cucumber, Gooseberry gourd, Paddy melon 

Synonyms: ​​Cucumis africanus, Cucumis dissectifolius, Cucumis dissectifolius,  Cucumis grossularoides, Cucumis merxmuelleri.

Form and function

Flowers

  • Male and female flowers produced on the same plant.
  • Male flowers in small clusters of 2 to 4 or short racemes.
  • Female flowers solitary or occasionally paired.
  • Yellow corolla with ovate lobes 4 to 5 mm long.

Prickly paddy melon flower © Martin Bennett

Leaves

  • Broadly ovate.
  • 25 to 75 mm long and 25 to 80 mm wide.
  • Divided into 3 to 5 lobes.
  • Lobes obovate and toothed to lobed.
  • Lower surface bristly hairy.
  • Upper surface sparsely hairy.
  • Borne on stalks 10 to 85 mm long.  

Prickly paddy melon leaf © Martin Bennett

Fruits

  • Small melon like fruit, globose to spherical (golf-ball sized; typically, 15 to 25 mm in diameter).
  • Green with paler longitudinal stripes, ripening yellow.
  • Surface with scattered soft bristles up to 6 mm long.
  • Each plant producing up to 50 or more fruits.
  • Each fruit containing up to 200 viable seeds.

Prickly paddy melon inside fruit © mrsdew17

Roots

  • Slender taproot with many, strong, shallow laterals.

Habitat

Often found in semi-arid temperate regions and can invade in a variety of environments, including grass lands, woodlands and other disturbed areas. Prefers soils with high phosphorous and brown clay soils which can retain soil moisture. Germinates in late spring when average daily temperature reached 22 °C and average night temperatures were greater than 15 °C.

How does it spread?

​​Dispersed by birds, waterway, machinery, garden/other waste, herbivorous mammals (e.g. rabbits and cattle).​ 

Why is it a weed?

  • Displaces native vegetation.

Similar species

Pie melon fruit © Guy Taseski

Similar non-native plants: Similar to pie melon (Citrullus lanatus, also called Citrullus amarus) however can be distinguished by its larger fruit (up to 15 cm diameter) without spines, and also larger brown seeds.

How to control

Arum Lily

Physical

Arum Lily

Chemical

Physical

 

Prickly paddy melon removal off site © DBCA

For isolated and small infestation, manual removal may be effective for immature plants before flowering. Make sure to remove any remaining mature fruits from sites to prevent resprouting.​ 

Image (right): Prickly paddy melon being removed off site in a ute on the Turquoise Coast.

 

 

Chemical

Chemical control is most effective on young seedlings and generally provides poorer results on mature plants. Apply metsulfuron (600g/L) at 4.2 g/ha with a wetting agent using a foliar application method (e.g. backpack or knapsack spraying).

Alternatively, spot spray using a foliar application method, with 2 mL of triclopyr in 10 L of water plus 25mL of a wetting agent, ensuring full leaf coverage.

Further
reading

Minor use permits
external link Permit PER96598 for metsulfuron
external link Permit PER96642 for triclopyr

Weed Distribution Map

LSID number: [51270837#tab_recordsView] | full LSID: [https://id.biodiversity.org.au/taxon/apni/51270837#tab_recordsView] | field_lsid: [] | taxon: [Cucumis myriocarpus]

ALA Reference

References

  • Bioscurity Queensland (2016) Cucumis myriocarpus Naudin - Fact Sheet
  • Board of Botanic Gardens and State Herbarium: Adelaide. (n.d.) Cucumis myriocarpus Naudin. Flora SA
  • Meadly, G. R. W. (1959) Weeds of Western Australia - Paddy melon (Cucumis myriocarpus Naud.)," Journal of the Department of Agriculture, Western Australia, Series 3: Vol. 8: No. 3, Article 10.
  • Pasture.io. (2024, March 25) Australia Leads The Way In Turning Invasive Weeds into Viable Economic Crops. Pasture.io.
  • Shaik, R. S., Burrows, G. E., Urwin, N. A. R., Gopurenko, D., Lepschi, B. J., & Weston, L. A. (2017) The biology and management of prickly paddy melon (Cucumis myriocarpus L.), an important summer annual weed in Australia. Crop Protection, 92, 29–40.
  • Western Australian Herbarium (2019) Florabase—the Western Australian flora. Department of Biodiversity, Conservation and Attractions.
  • WeedScan (2026) Prickly paddy melon

Life Cycle

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Notes
Germination
Active growth
Flowering
Fruiting
Regularly or most commonly
Occasionally, given suitable conditions

Management

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Notes
Physical
Chemical
Optimal
Potentially, but conditionally dependent
Last updated: September 2026