Ivy gourd
C. grandis is a fast-growing perennial vine with a tuberous root stock producing annual stems that grows several metres long. It quickly covers near by plants and can form dense mats.
Naturalised in northern Queensland and in the coastal districts of northern Western Australia (e.g. Broome, South Hedland and Arnhem Land). Possibly also naturalised, or naturalised beyond its native range, in the Northern Territory.
Ivy gourd (Coccinia grandis) prefers the dry rainforests of the monsoon zone, the tropical and sub-tropical rainforests of the humid coastal zones, and riparian vegetation in these and other locations.
This very aggressive smothering vine is regarded as being native to some parts of the Northern Territory. However, it is invasive in other parts of the world and it thought to pose a threat to the environment in many parts of Australia beyond its native range (i.e. in the monsoon zone of northern Australia and the tropical and sub-tropical humid zones of coastal Queensland and northern New South Wales).Ivy gourd (Coccinia grandis) could infest the dry rainforests of the monsoon zone, the tropical and sub-tropical rainforests of the humid coastal zones, and riparian vegetation in these and other locations. This species is already a significant environmental weed in Hawaii, where it smothers remnant native vegetation. It climbs and envelops shrubs and trees, forming a dense canopy that impedes light penetration and prevents the growth and regeneration of native plants.
An environmental weed, but hosts pests and diseases of horticultural Cucurbitaceae crops.
Its leaves are arranged alternately along the stems; they vary from heart to pentagon shape and are up to 10 cm wide and long. The upper surface is hairless, lower surface hairy and bearing three to eight glands near attachment of leaf stalk with major vein branching. Margin of the leaf notched. Leaf tip is blunt. Leaf petioles (stalks) one to three centimetres long. Tendrils are unbranched.
C. grandis is dioecious (male flowers are produced on separate plants to female flowers). Flowers are large, white and star-shaped. The calyx has five subulate, recurved lobes, each 2–5 mm long on the hypanthium; peduncle 1–5 cm long. The corolla is campanulate, white, 3–4.5 cm long, deeply divided into five ovate lobes. Each flower has three stamens (present as staminodes in female flowers). The ovary is inferior. The fruit is red (when ripe), ovoid to elliptical, 25–60 mm long, 15–35 mm in diameter, hairless on stalks 10–40 mm long. Seeds are tan-coloured and 6–7 mm long.
C. grandis can be dispersed from seeds as well as from broken pieces of roots and stems. Seeds can be dispersed by birds and feral pigs (PIER 2003). Seeds do not exhibit dormancy and usually germinate within 2–4 weeks at 20 °C.
