Stapelia gigantea
Introduction
Stapelia gigantea has the largest flowers (up to 40 cm across) of any plant in our region and is one of the easiest stapeliads to grow. Plants are widely available from most nurseries and it is an ideal plant for water-wise rockeries or as large container plants in small gardens. As its vernacular name indicates, the flowers smell of rotting flesh and attract all kinds of flies, so it is advised to plant it in appropriate areas in the garden.
Fig. 1. Flowering plant of Stapelia gigantea in habitat. (Photo Cameron McMaster)
Description
Description
This is a very variable species, with erect, succulent, perennial stems, up to 25 cm tall, branching strongly from the base and spreading vegetatively. Stems are usually green but may turn reddish-purple when exposed to direct sunlight. Members of the genus Stapelia can be recognised by their fleshy, 4-angled, velvety stems that are covered in short hairs, are seemingly leafless (leaves reduced to minute scales) and contain clear sap.
Fig. 2. Stems of Stapelia gigantea turning purplish in direct sunlight. (Photo SP Bester)
Flowers are carried near the base on a short peduncle and 1 to 5 flowers develop successively. Flowers have a strong, unpleasant scent. They are large, 12–40 cm in diameter, star-shaped, with an open, saucer-shape. The petals are a pale yellow, yellowish cream or biscuit colour, are covered with pale purple hairs and have irregular, transverse, crimson to maroon-red ridges on the inside, that give the bloom a pinkish appearance. Plants may flower throughout the year, depending on climatic conditions, but they mainly flower in mid to late summer (from December to April).
Fig. 3. Flowers of Stapelia gigantea develop successively from the base of the stems. (Photo Adam Shuttleworth)
Fig. 4. Saucer-shaped flower of Stapelia gigantea. (Photo Olivier Maurin)
A pair of follicles usually develops from successfully pollinated flowers and can but up to 30 cm long and about 2.5 cm in diameter. These follicles contain numerous seeds. Each seed has a fluffy white coma that expands as it dries, when the fruit bursts open.
Fig. 5. Stapelia gigantea. A. typical pointed flower bud (Photo Olivier Maurin). B. Follicle or fruit splitting releasing seed with a tuft of hairs at its upper side. (Photo Karin van der Walt)
Conservation Status
Status
The current conservation status of the species is Least Concern (LC), but plants are becoming more scarce and in many populations are extensively harvested for their medicinal and ornamental value.
Fig. 6. Distribution records of Stapelia gigantea from the National Herbarium in Pretoria.
Distribution and habitat
Distribution description
The species is naturally restricted to the southern parts of Africa, and is native to Angola, Botswana, Lesotho, Malawi, Mozambique, Namibia, Swaziland, Zambia, Zimbabwe and South Africa, where it occurs in the Western, Eastern and Northern Cape, North West, Free State, KwaZulu-Natal, Limpopo, Mpumalanga and Gauteng Provinces. The species is introduced to Hawaii, India, Kenya and Tanzania.
Plants commonly grow in arid and sparsely vegetated areas and on rocky outcrops. They can also be found in partial shade of bush-clumps and on the edges of rock sheets, in open or closed woodland and savannah; frequently in sandy to loam soils, at altitudes ranging from 325–1 100 m.a.s.l.
Fig. 7. Various habitats of Stapelia gigantea. A. Grassland (Photo Geoff Nichols). B. Shaded savanna (Photo Geoff Nichols). C. Rocky outcrops and crevices. (Photo Judd Kirkel-Welwitsch)
Derivation of name and historical aspects
History
The genus Stapelia was named by Linnaeus, when he described it 1737. This was in honour Johannes Bodaeus von Stapel, a 17th century physician, botanist and editor, who collected and grew the plants that were presented to Linnaeus. The epithet gigantea refers to the huge flowers of this species – the largest found in the genus. The genus Stapelia currently consists of 31 accepted species, and is still upheld despite the new combinations that were made in the genus Ceropegia in 2017. The other large-flowered species that are closely related are Stapelia grandiflora, which has an Eastern Cape distribution; S. leendertziae, which has purple bell-shaped flowers and S. gettliffei, which is more hairy and has distinct leaves (the largest in the genus), appearing as white along the angled flanks on the stems.
Fig. 8. Stapelia species related to S. gigantea: A. S. leendertziae. B. S. grandiflora; C. S. gettliffei (Photos A, C, Geoff Nichols; B, Marinda Koekemoer).
Ecology
Ecology
The flowers have a strong smell of decaying flesh (hence carrion flowers), which attracts insects for pollination (mainly flies – myophily). Plants are thus strictly entomophilous (strongly associated with insects). Plants occupy a wide diversity of habitats, mostly in arid areas. It is not uncommon to see flowers covered with the eggs of flies that were deceived by the odour and thus laid their eggs around the fleshy corona, convinced that it would be a food source for their hatching larvae.
Fig. 9. Central portion of flower of Stapelia gigantea with fly as possible pollinator – note also the various fly eggs. (Photo Martin Heigan)
The male and female parts of the flower and various membranes and sacs are fused into a complex structure which usually traps the mouthparts or legs of insects. A clip attached to two pollen sacs of the plant becomes attached to an insect in its struggle to free itself. This is deposited on the next flower visited, where the pollen germinates, causes fertilisation and the development of seeds.
Fig. 10. Corona lobes of A. Stapelia gigantea (Photo SP Bester) and B. S. grandiflora (Photo Marinda Koekemoer) showing the different morphology of these structures.
Individual flowers are mostly short-lived, but in some cases, plants have extended flowering periods through the sequential formation of new flowers, under favourable conditions.
The light seed, with its coma and wing-like margin, is adapted to wind dispersal.
Most species appear to be relatively short-lived under natural conditions. They are generally widely scattered, and populations sometimes vary considerably in density over time, even disappearing from a locality where they were previously plentiful. Naturally, plants establish easily from either seed or vegetatively, from stems that are scattered by animals and root easily.
Uses
Use
Stapelia gigantea has many medicinal and cultural (magic) uses and is traditionally used as an emetic to treat hysteria, but also has analgesic and purgative effects. It is also used to treat pain of bruised skin by rubbing ash from burnt plants into the wounds. Crushed stems are used, mixed with various other plants, as a proactive charm and sprinkled on family members to protect them from the ‘pollution’ of visitors. This is also one of the species planted near homesteads to ward off lightning. Plants are apparently also traditionally used as poison that may lead to death.
Fig. 11. Stapelia gigantea in a flowerbed at the Pretoria National Botanical Garden. (Photo SANBI)
The giant carrion flower is widely cultivated in gardens and parks, not only in South Africa, but also across the world where it is usually grown as a container plant. This large-flowered species makes a good show when grown in masses in the garden. Plants are reasonably drought-resistant succulents, ideal for rockeries, and suitable as container plants. They are excellent subjects for a water-wise garden. The sterile stems are very attractive when planted in full sunlight. When in full flower, pollinators are attracted by the odour. For the eco-friendly gardener this is a way of attracting food for birds and reptiles such as lizards to the garden.
Growing Stapelia gigantea
Grow
Carrion flowers grow very easily in all parts of South Africa. Grow in direct sunlight throughout the year – this will encourage flowering. They will also grow in light, semi-shade in hot climates. The soil should a well-drained, sandy medium consisting of equal parts of washed river sand, potting soil and topsoil and a pH of 6.5–7.5.
Provided that they are not over-watered and are given a warm position, your Stapelia will flower successfully. When grown in containers water from below. Too much water leads to rotting from the base and too little water causes the plants to shrink and die from the tips. Rather water plants sparingly than excessively. The plants require a period without water in winter (a dormant phase). They can survive long periods without water, but be sure to water them before they shrink too much and will not be able to recover.
Grow plants in warm, dry places, if the temperature gets too low (below 15°C) or too moist, plants easily develop black spot and other fungal diseases. Fungicide is best applied during the dormant (winter) season as it may inhibit flowering and growth during the active season.
If needed, plants can be fed with liquid fertiliser during the active growing phase (spring and summer). Plants grow rapidly. When grown in containers and plants are crowding against the rims of containers, consider transplanting, but do this in spring just before active growing starts.
Fig. 12. Seeds of Stapelia gigantean germinate easily to produce A. seedlings (Photo Geoff Nichols) and B. young plants. (Photo Cameron McMaster)
Propagation by seed is easy. Sow seed in a well-drained, sandy medium, these will germinate within a week at 21°C. Truncheons already with roots can be taken from large plants and planted directly. Cuttings can be made with a clean sharp knife, leave the cuttings for 4–5 days, allow the ends to air dry and then plant these in a well-drained sandy medium, leave these for 3–4 weeks without directly watering the severed ends to prevent rotting. When roots have been established, water sparingly.
Woolly aphids on the roots and underground stems and mealy bugs on the stems and bases are the most common problems. A strong jet of water or a 50:50 mix of methylated spirits and water can be used to eradicate these pests.
Black rot, a secondary infection after woolly aphid attacks, is also problematic. Remove all traces of black rot with a sterile knife, spray the plant with a fungicide such as Benlate (a.i. benomyl) and dust with flowers of sulphur. As soon as stem rot is noticed, the affected parts should immediately be cut away and destroyed.
See the Stapelia contribution in this series for further cultivation instructions.
References
- Bester, S.P. 2006. Stapelia L. (Apocynaceae). PlantZAfrica. Online. http://pza.sanbi.org/stapelia.
- Bruyns, P.V. 2005. Stapeliads of southern Africa and Madagascar. Umdaus press, Hatfield, Pretoria.
- Court, D. 2000. A revised Succulent Flora of southern Africa. Balkema, Rotterdam.
- Huxley, A. (ed.). 1981. Success with house plants. Reader’s Digest. Pleasantville, New York.
- Du Randt, F. 2018. The Sand Forests of Maputaland. South African National Biodiversity Institute, Pretoria.
- Frandsen, R. 2017. Succulents of southern Africa. Honeyguide Publications, Somerset West.
- Germishuizen, G. & Fabian, A. 1997. Wild flowers of northern South Africa. Fernwood Press, Vlaeberg, Cape Town.
- Hardy, D. & Fabian, A. 1992. Succulents of the Transvaal. Southern Book Publishers, Halfway House, South Africa.
- Leach, L.C. 1985. A revision of Stapelia L. (Asclepiadaceae). Excelsa Taxonomic Series 3: 1–157.
- Leistner, O.A. (ed.). 2000. Seed plants of southern Africa: families and genera. Strelitzia 10. National Botanical Institute, Pretoria.
- Lucas, A. 1987. Wild Flowers of the Witwatersrand. Struik Pubishers, Cape Town.
- Müller, B. & Albers, F. 2002. Stapelia in F.Albers & U.Meve (eds.) Illustrated Handbook of Succulent Plants. Springer, Berlin.
- Oliver, I.B. 1998. Grow succulents. Kirstenbosch Gardening Series. National Botanical Institute, Cape Town.
- Pooley, E. 2005. A field guide to wild flowers KwaZulu-Natal and the eastern region. The Flora Publications Trust, Durban.
- Retief, E. & Herman, P.P.J. 1997. Plants of the northern provinces of South Africa: keys and diagnostic characters. Strelitzia 6. National Botanical Institute, Pretoria.
- Smith, C.A. 1966. Common names of South African plants. Memoirs of the Botanical Survey of South Africa No. 35. Government Printer, Pretoria.
- Smith, G.F., Crouch, N.R. & Figueiredo, E. 2017. Field guide to succulents in southern Africa. Struik Nature, Cape Town.
- Van Wyk, B.-E. & Gericke, N. 2000. People's plants, a guide to useful plants of southern Africa. Briza Publications, Pretoria.
- Victor, J.E. 2005. Stapelia gigantea N.E.Br. National Assessment: Red List of South African Plants version 2020.1. Accessed on 2021/03/21
Credits
Stoffel Petrus Bester
National Herbarium (PRE) / Foundational Research and Services Division
April 2021
Acknowledgements: the author thanks photographers Cameron McMaster, Adam Shuttleworth, Olivier Maurin, Karin van der Walt, Geoff Nichols, Judd Kirkel-Welwitsch, Marinda Koekemoer and Martin Heigan (cited with each image) for permissions to use their images.
Plant Attributes:
Plant Type: Ground Cover, Succulent
SA Distribution: Eastern Cape, Free State, Gauteng, KwaZulu-Natal, Limpopo, Mpumalanga, North West, Northern Cape, Western Cape
Soil type: Sandy, Loam
Flowering season: Spring, Early Summer, Late Summer
PH: Alkaline, Neutral
Flower colour: Purple, Pink, Cream, Yellow
Aspect: Full Sun, Morning Sun (Semi Shade), Afternoon Sun (Semi Shade)
Gardening skill: Easy
Special Features:
Drought resistant
Feature plant
Fragrant
Good potplant
Medical plant
Horticultural zones
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