Blue trumpet, blue sky or Bengal clock vine
Thunbergia grandiflora, Fam. Acanthaceae
Vigorous, twining perennial vines with long slender climbing stems and large tuberous root systems. Tubers as large as 70 kg have been recorded.
| Weed Category: |
Restricted invasive plants Category 3 Plants declared invasive under the Biosecurity Act 2014, that are present in QLD.
Not to be distributed or disposed of.
|
| Weed: | Yes |
| Form or habit: | Vine (Climbing, Twining or groundcover) |
| Family: | Acanthaceae |
| Leaf: | Simple Opposite Simple, opposite, triangular, 60-210 x 55-205mm, pointed tip, scalloped or lobed margins, both sides coarsely hairy. |
| Flower conspicuous: | Conspicuous |
| Flower colour: |
Blue, Purple, Violet |
| Flower description: | Trumpet-shaped with short tube and five spreading petals. Petals pale lavender-blue, throat yellowish, outside usually white; up to 80 x 6-8mm, in terminal racemes or occasionally solitary. |
| Fruit conspicuous: | Conspicuous |
| Fruit colour: |
Brown |
| Fruit: | Dry |
| Fruit description: | Brown, cone-shaped capsules with rounded base contain four flat seeds that are explosively expelled at maturity. Capsules 30-50mm long, seeds up to 10mm long, covered in brown scales. Viable seeds are produced, contrary to earlier beliefs. |
| Habitat: | |
| Distribution | |
| Food source for: | |
| Toxicity: | No toxicity known |
| Origin: | Northern India and tropical Africa |
| Notes: | Spread by: garden waste, water, contaminated soil containing vegetative material. Propagation is mostly from stem cuttings or shoots from the tuberous roots, particularly if damaged. Invades/threats: creek banks, native remnant vegetation; smothers vegetation pulling down mature trees. Notes: introduced as garden ornamentals, now serious environmental weeds. They are difficult to control due to their extensive tuberous root systems. If detected, early control is essential and existing garden plants should be destroyed. Four species are declared in Queensland and another species, though not declared, is already in environmental areas within this district. Annual thunbergia (T. annua), category 1 restricted invasive plant, not known to occur in Queensland. Thunbergia grandiflora is a Category 3 restricted invasive plant under the Biosecurity Act 2014, it must not be given away, sold, or released into the environment without a permit. The Act requires everyone to take all reasonable and practical steps to minimise the risks associated with invasive plants and animals under their control. This is called a general biosecurity obligation (GBO). |
| Information sources: | Mackay Regional Pest Management Group (2018) Weeds of the Mackay Whitsunday Region Second Edition. |
