Thunbergia grandiflora
|
Taxon |
Family |
|
Thunbergia grandiflora Roxb. |
Acanthaceae |
 |
 |
| Flowers and leaves of Thunbergia grandiflora. Author: Institute for Systematic Botany |
The plant in invaded habitat of Queensland, Australia. |
Common names: Bengal trumpet, Trumpet vine, Blue trumpet vine, Skyvine, Bengal clockvine, Clockvine, Bengal trumpet vine, Skyflower vine, Blue skyflower.
Synonyms: Flemingia grandiflora Roxb. ex Rottler; Pleuremidis grandiflora (Roxb.)Raf.; Thunbergia cordifolia (Nees)
Life form: Liana
Biology/Ecology:
Dispersal: Spreads vegetatively by stolons, dispersal often by stem and tuber pieces carried by water. Also produces seed pods containing four seeds which are catapulted several metres when the pod splits. Dispersed by humans for use as an ornamental plant.
Reproduction: Produces trumpet-shaped lavender/blue flowers. Seed pods are 3 to 5 cm long. Seeds are up to 1 cm long.
Herbivores: Spider mites, whiteflies, scale insects.
Resistant stages: Extensive tuberous root system can be weigh up to 70kg. Root system persistently sprouts from its many buds when cut. Seeds (5-10mm wide) contained in seed pods.
Habitat:
Native habitat: Subtropical scrub of moist gullies and slopes.
Habitat occupied in invaded range: Tropical forests and forest edges, riparian zones, coastal areas.
Habitat requirements:
| Altitude | No information available. |
| Light | Shade tolerant. |
| Temperature | Prefers warm climates. |
| Annual rainfall | Prefers wet climates. |
| Soil | No information available. |
Distribution:
Native to India.
Introduced range: Invasive in Hawaii, Australia, southeastern USA, Singapore and Seychelles. Introduced but not considered invasive in Tanzania and tropical South America.
Impacts:
Ecosystem: The plant spreads rapidly and continually sprouts from its roots. Climbers are vigorous and smother vegetation below 12 metres above ground, reducing light levels for lower vegetation. The weight of the stems can kill trees during infestations. The plant is capable of invading primary and secondary forests.
Health, social and economic: Tubers can damage river banks, paths, fences and building foundations.
Management:
Mechanical: Small plants can be dug out, but more established plants have extensive underground tubers so are difficult to fully remove.
Chemical: Chemical control is often the only available option. Systemic herbicides such as Arsenal 250A (750 mL / 100 L) and imazapyr have reportedly been effective in killing the plant. Herbicides should be applied as a foliar spray. If the tubers are accessible, herbicides can be injected or applied through cuts. Good application technique is important in order to avoid killing non-target plants, and ongoing monitoring is needed as one application rarely kills the plant fully.
Biological: No information available.
References:
Starr, F., Starr, K., Loope, L., 2003. Thunbergia grandiflora. PIER. Available from http://www.hear.org/Pier/pdf/pohreports/thunbergia_grandiflora.pdf (Accessed August 2006).
Land Protection Australia, 2006. Thunbergia species. Land Protection, Queensland Goverment Australia. Available from http://www.nrm.qld.gov.au/factsheets/pdf/pest/pp23.pdf (Accessed August 2006).
Weber, E., 2003. Invasive Plant Species of the World: A Reference Guide to Environmental Weeds. CABI Publishing, Wallingford, UK.
Last updated October 2006
