Scientific name

Cardiospermum grandiflorumSw.

Synonyms

Cardiospermum barbicule Bak.; Cardiospermum hirsutumWilld

Common names

Balloon vine, heartseed, heartseed vine

Family

Sapindaceae

Origin

Cardiospermum grandiflorum is native to the tropical America (Brazil and eastern Argentina) though its native range may extend into southern Mexico and the Caribbean.

Naturalised distribution (global)

Locations within which Cardiospermum grandiflorum is naturalised include tropical areas of Australia, and southern and eastern Africa.

Introduced, naturalised or invasive in East Africa

Cardiospermum grandiflorum is invasive in parts of Kenya and Uganda (A.B.R. Witt pers. obs.) and in Tanzania. It is very common in urban open spaces, in disturbed areas and riparian zones (banks of watercourses).

Habitat

Cardiospermum grandiflorum has been recorded as invading forest margins, riparian zones, woodlands and urban open spaces.

Description

Cardiospermum grandiflorum is long-lived (perennial) climber-vine or climber with ribbed stems. The stems, flower stalks and fruits are all covered in short, stiff, bristly hairs.

Leaves are (compound) made up of 3 lots of 3 leaflets. Leaflets are toothed or lobed. Leaves may be up to about 16cm long.

Flowers have four petals, are white, fragrant and occur in clusters. The stalk of the flowerhead ends in a pair of tendrils.

The fruit is a membranous and inflated capsule (the "balloon") which is green, drying to brown. Seeds are round and black with an oblong to heart-shaped spot (hilum).

Reproduction and dispersal

Cardiospermum grandiflorum reproduces by seeds, which are transported by wind and water, mostly while attached to membranous inner walls of the fruit.

Similar species

Cardiospermum grandiflorum is very similar to another closely related species, Cardiospermum halicacabum (known as small balloon vine). These two species can be distinguished by the following differences:

• C. grandiflorum has relatively large leaves (6-16 cm long) and densely hairy younger stems. Its flowers (6-11 mm long) and the papery capsules (5-6.5 cm long) are relatively large and pointed. The seed of C. grandiflorum has an oblong to heart-shaped hilum..
• C. halicacabum has relatively small leaves (4-12 cm long) and finely hairy to almost hairless (puberulent to sub-glabrous) younger stems. Its flowers (3-4 mm long) and papery capsules (1-3 cm long) are also rounded and relatively small. The seed of C. halicacabum has a kidney-shaped hilum.

Economic and other uses

Cardiospermum grandiflorum has been introduced outside its native range as a garden ornamental. However, these uses cannot compensate for this plant's overall negative impacts.

Environmental and other impacts

Cardiospermum grandiflorum forms dense infestations that outcompete indigenous vegetation. It is a major weed in riparian zones (banks of watercourses) in South Africa. It is rapidly spreading beyond urban areas in East Africa.  Although not a very serious problem yet in the region, it has massive potential for further spread. It can smother native plants and prevent the free movement of wildlife so has great potential to negatively impact upon biodiversity.

C. grandiflorum has been included in the Global Invasive Species Database (GISD 2008). It has been listed as a noxious weed in South Africa (prohibited plants that must be controlled. They serve no economic purpose and possess characteristics that are harmful to humans, animals or the environment) and in in the Australian states of New South Wales and Queensland, Australia.

Management

The precise management measures adopted for any plant invasion will depend upon factors such as the terrain, the cost and availability of labour, the severity of the infestation and the presence of other invasive species. Some components of an integrated management approach are introduced below.

The best form of invasive species management is prevention. If prevention is no longer possible, it is best to treat the weed infestations when they are small to prevent them from establishing (early detection and rapid response). Controlling the weed before it seeds will reduce future problems. Control is generally best applied to the least infested areas before dense infestations are tackled. Consistent follow-up work is required for sustainable management.

Young plants can be hand-pulled or dug out. Plants can be cut at the base, leaving top growth to die off in and then the root dug out.

Large individual vine stems can be cut close to the ground and the stem cut painted with 100% Glyphosate. Situations where hundreds of vine stems are growing together ("curtain infestations") can be cut at waist height and the top growth will die off and eventually fall out of the canopy. Chemical management of Cardiospermum grandiflorum can be difficult where it grows close to water sources. When using any herbicide always read the label first and follow all instructions and safety requirements. If in doubt consult an expert.

In South Africa, several species of insects from South America are being investigated as potential biological controls for C. grandiflorum (A.B.R. Witt pers. comm.).

Legislation

Not listed as a noxious weed by the state or governments in Kenya, Tanzania and Uganda.

References

GISD (2008). Global Invasive Species Database online data sheet. Cardiospermum grandiflorum (vine, climber). www.issg.org/database. Accessed March 2011.

Henderson, L. (2001).  Alien weeds and invasive plants. A complete guide to declared weeds and invaders in South Africa.  Plant Protection Research Institute Handbook No. 12, 300pp. PPR, ARC South Africa.

Editors

Agnes Lusweti, National Museums of Kenya; Emily Wabuyele, National Museums of Kenya, Paul Ssegawa, Makerere University; John Mauremootoo, BioNET-INTERNATIONAL Secretariat - UK.

Acknowledgments

This fact sheet is adapted from The Environmental Weeds of Australia by Sheldon Navie and Steve Adkins, Centre for Biological Information Technology, University of Queensland. We recognise the support from the National Museums of Kenya, Tropical Pesticides Research Institute (TPRI) - Tanzania and Makerere University, Uganda. This activity was undertaken as part of the BioNET-EAFRINET UVIMA Project (Taxonomy for Development in East Africa).

Contact

BioNET-EAFRINET Regional Coordinator: [email protected]