Click on images to enlarge
close-up of hairy young shoot (Photo: Sheldon Navie)
close-up of stem, with adventitious roots beginning to form, and leaf stalk (Photo: Sheldon Navie)
close-up of leaf underside (Photo: Sheldon Navie)
climbing habit (Photo: Sheldon Navie)
leaves and bluish flowers (Photo: Sheldon Navie)
three-lobed leaf (Photo: Sheldon Navie)
heart-shaped leaf (Photo: Sheldon Navie)
leaves and purplish flowers (Photo: Sheldon Navie)
habit growing on a fence (Photo: Sheldon Navie)
flower from side-on, showing paler floral tube with long and narrow sepals (Photo: Sheldon Navie)
close-up of flower with paler centre (Photo: Sheldon Navie)
tubular flowers (Photo: Sheldon Navie)
large infestation (Photo: Land Protection, QDNRW)
the similar ivy-leaf morning glory (Ipomoea hederacea) has smaller flowers and strongly curved sepals (Photo: Sheldon Navie)
Ipomoea indica (Burm.) Merr.
Convolvulus acuminatus Vahl; Convolvulus congestus (R. Br.) Spreng.; Convolvulus indicus Burm.; Ipomoea acuminata (Vahl) Roem. & Schult.; Ipomoea cataractae Endl.; Ipomoea congesta R. Br.; Ipomoea insularis (Choisy) Steud.; Ipomoea leari Paxton; Ipomoea learii Paxton; Pharbitis insularisChoisy
Blue dawn flower, blue dawn-flower, blue dawnflower, blue morning glory, blue morning-glory, blue morningglory, common morning glory, convolvulus, dunny creeper, Lear's morning glory, morning glory, ocean blue morningglory, oceanblue morning glory, oceanblue morning-glory, oceanblue morningglory, purple morning glory, purple morningglory.
Locations within which Ipomoea indica is naturalised include the coastal districts of eastern Australia, southern Europe, southern New Zealand, southern USA, Pacific islands and eastern and southern Africa.
Ipomoea indica is cultivated in gardens in Kenya, and the north-eastern corner of Tanzania and in Uganda. It has since become naturalised in all three countries.
This species inhabits wetter tropical, subtropical and temperate regions. It is particularly common in suburban gullies, gardens, along roadsides, in riparian zones (banks of watercourses) and in disturbed rainforest. Ipomoea indica invades woodland, degraded land, arable land, roadsides, riverbanks, coastal dunes.
The stems usually develop a twining habit although they occasionally spread across the ground (they are sometimes prostrate). These stems are fairly densely covered in spreading or backwards-curved (retrorse) hairs when young and they occasionally also exude a white milky sap when broken.
The alternately arranged leaves (5-18 cm long and 3.5-16 cm wide) are borne on stalks (petioles) 2-18 cm long. They range from heart-shaped (cordate) to obviously three-lobed and have pointed tips (acute apices). Both leaf surfaces are softly hairy, the undersides more so.
The funnel-shaped (tubular) flowers are bright blue or bluish-purple in colour with a paler pink or whitish-pink central tube. These large flowers (5-10 cm long and 7-10 cm across) are borne in clusters of two to twelve in the leaf forks (axils). They have five long and narrow sepals (14-22 mm long). Flowering can occur throughout the year.
Ipomoea indica reproduces primarily from broken fragments of stems that produce new roots at the nodes. Hence a common mode of dispersal is believed to be as a consequence of gardeners dumping unwanted vegetative material. It may also be dispersed by vehicles.
Ipomoea indica is very similar to Ipomoea cairica (coastal morning glory), Ipomoea purpurea (common morning glory) and Ipomoea hederacea (ivy-leaved morning glory). These species can be distinguished by the following differences:
Ipomoea indica has been widely cultivated as a garden ornamental. However, this cannot compensate for this plant's overall negative impacts.
Ipomoea indica regenerates prolifically and tends to outcompete indigenous vegetation, especially in disturbed areas and degraded land.
It has been listed as a noxious weed in some states 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 as a Category 3 invader in others (no further planting is allowed - except with special permission - nor is trade in propagative material. Existing plants must be prevented from spreading) in others and a noxious weed in New South Wales, Australia.
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.
Plants can be hand pulled and the roots dug out roots (all year round). Roots can be buried deeply and the remaining plant material left to rot down on site.
Plants can be cut down and stumps painted with a suitable herbicide. When using any herbicide always read the label first and follow all instructions and safety requirements. If in doubt consult an expert.
Slashed stems resprout so there must be follow up and retreatment as necessary to ensure that long term control is achieved.
Not listed as a noxious weed by the state or governments in Kenya, Tanzania and Uganda.
Global Compendium of Weeds. www.hear.org/gcw. Hawaiian Ecosystems at Risk Project. 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.
Lazarides, M., Cowley, K. and Hohnen, P. (1997). CSIRO Handbook of Australian Weeds. CSIRO Publishing, Collingwood, Victoria.
Agnes Lusweti, National Museums of Kenya; Emily Wabuyele, National Museums of Kenya, Paul Ssegawa, Makerere University; John Mauremootoo, BioNET-INTERNATIONAL Secretariat - UK.
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).
BioNET-EAFRINET Regional Coordinator: [email protected]