Description
Laurel Clock Vine (Thunbergia laurifolia) is a a vigorous, perennial climbing vine with tuberous roots. Its stems and leaves are gland-dotted. The leaves are oval-shaped, not lobed, and narrow to a pointed tip, and are mostly 130-190 mm long and 50-90 mm wide. Towards the end of the branches there are 4 trumpet-shaped flowers at each of the nodes. The flowers are on stalks up to 17 mm long and the flower begins as a short broad tube, white on the outside with a yellowish throat, and opens out into five rounded, pale lavender-blue petals, one larger than the others. The flowers are up to 80 mm long and 60-80 mm across, and are borne in clusters on long, drooping branches. The seed capsule is brown and inconspicuous, oval-shaped with pinched ends (i.e. elliptical), 10 mm long and 4 mm wide. The capsules usually contain two to four hemispherical seeds which have a hollow inner surface like a cap. The seeds are less than 10 mm in diameter and covered with brown scales.
For further information and assistance with identification of Laurel Clock Vine contact the herbarium in your state or territory.
Distribution:
Scattered populations of Laurel Clock Vine are found in the Cairns area of northern Queensland and in south-eastern Queensland. It has not been recorded for the Northern Territory in their checklist of plants although it is known as an ornamental in Darwin. It also occurs on the Daly River, southwest of Darwin.
Habit:
Vine
Key points:
- Laurel Clock Vine (Thunbergia laurifolia) is a vigorous, perennial, climbing vine that is capable of smothering vegetation in tropical rainforest areas.
- Thunbergia species are a major threat to remnant vegetation in the Wet Tropics.
- Early intervention is crucial otherwise the tuberous system of roots make them difficult to remove.
- Take care when disposing of Laurel Clock Vine because garden waste is a frequent source of new weed infestations.
How it spreads:
Dispersal is by seeds, cuttings, and fragments of stems and roots; the root tubers formed can be enormous. Dumping of garden cuttings is a likely means of spread since new plants can be produced from the nodes and from the tuberous roots, or through contaminated earth being removed for fill or other soil use. Infestations along riverbanks have been caused by root pieces breaking off and being transported further downstream by floodwaters. Seed production is by far the least effective means of dispersal of the plant.
Where it grows:
Laurel Clock Vine is found along riverbanks, in disturbed forest areas, particularly in the margins, in open woodlands, on roadsides and fence-lines in tropical and subtropical regions.
Flower colour:
Blue
Distribution map:
Impacts:
Laurel Clock Vine is on the Alert List for Environmental Weeds, a list of 28 non-native plants that threaten biodiversity and cause other environmental damage. Although only in the early stages of establishment, these weeds have the potential to seriously degrade Australia’s ecosystems.
Laurel Clock Vine is a major threat to monsoon vine thickets and remnant tropical rainforests across northern Australia. Its ability to climb to the top of tall trees as well as across the top of lower vegetation eventually smothers the species supporting them, often native vegetation, and may even lead to the toppling of mature trees because of the weight of the vine. It is particularly prevalent in areas on the edges of rainforest margins where light has been introduced.
Origin:
Laurel Clock Vine is native to India, Myanmar and Malaysia, but has been cultivated throughout the tropics for its ornamental flowers.
