Click on images to enlarge
seedling (Photo: Sheldon Navie)
purplish flower (Photo: Sheldon Navie)
mature fruit (Photo: Sheldon Navie)
pinkish flower from side-on, showing the long and relatively broad sepals (Photo: Sheldon Navie)
habit (Photo: Sheldon Navie)
hairy younger stem (Photo: Sheldon Navie)
close-up of leaf (Photo: Sheldon Navie)
close-up of seeds (Photo: Steve Hurst at USDA PLANTS Database)
Ipomoea purpurea (L.) Roth
Convolvulus purpureus L.; Ipomoea hirsutulaL.
Common morning glory, annual morning glory, morning glory, morning glory, purple morning glory, tall morning glory, tall morning-glory
Convolvulaceae
The exact native range of Ipomoea purpurea is obscure, however it is thought to have originated in South America.
Ipomoea purpurea is widely naturalised in the tropics.
Ipomoea purpurea is naturalised in parts of Kenya and has been introduced to Tanzania and Uganda. In East Africa, it occurs in Mengo district (Uganda), Kiambu district (Kenya) and Lushoto district (Tanzania).
Ipomoea purpurea invades waste and cultivated ground mainly in riparian (banks of watercourses), wetland and coastal habitats.
Ipomoea purpurea is a herbaceous annual twining climber. Stems of Ipomoea purpurea are hairy and may be trailing or twinning. The leaf blade is ovate (egg-shaped in outline with broad end at base), entire or 3-lobed, acuminate (gradually tapering to a sharp point) at the apex, cordate (heart-shaped) at the base, glabrous or pubescent (hairy).
Flowers of I. purpurea are solitary or in few-flowered cymes. The stalk of the inflorescence (peduncle) is up to 12 cm long. Sepals finely pubescent all over; corolla is white, pink or magenta, and white below.
Ipomoea purpurea was introduced as a garden ornamental and is still occasionally grown in gardens.
Ipomoea purpurea is mainly a weed of agricultural areas and disturbed sites (e.g. crops, roadsides, parks, gardens, fence-lines and waste areas). However, it also invades bushland and riparian zones (banks of watercourses) and can be a serious environmental weed in warm moist areas, where it chokes out native plants. Once established in areas of indigenous vegetation, it is able to outcompete native species for nutrients, water and sunlight. Its spreads mainly along riparian zones. Parts of this plant, including the seed are poisonous if ingested.
I. purpurea has been listed as an invader in South Africa.
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.
The editors do not know of any biological control programmes targeted at this species.
Not listed as a noxious weed by the state or governments in Kenya, Tanzania and Uganda.
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.
Verdcourt., B. (1963). Convolvulaceae. Flora of Tropical east Africa.
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]