Adenium multiflorum is the best known of the South African
adeniums. It flowers in winter when most of the surrounding vegetation
is rather dull in comparison to the brilliant white, pink, crimson,
red and bicoloured flowers that cover these plants when in full
bloom. The genus Adenium consists of five succulent species
from tropical Africa, Arabia and Socotra. Their striking forms and
beautiful flowers borne in masses over a long period make them excellent
garden and container plants.
Adenium multiflorum is a deciduous succulent shrub or small
tree, 0.5-3 m tall, the shape resembling a miniature baobab. Stems
arise from a large underground rootstock. The bark is shiny grey
to brown, with poisonous watery latex. For most of the year the
plants do not have flowers or leaves. The leaves are up to 100 mm
long, shiny green above and pale below, usually much broader towards
the tip, and are carried in clusters at the growing tips of the
branches. They are shed before flowering.
The flowers are borne in terminal inflorescences, each flower 50-70
mm in diameter. They vary greatly in colour, usually with pointed
white lobes, crinkly red margins and red stripes in the throat.
Plants with pure white flowers are occasionally found. The flowers
are sweetly scented. Flowering occurs from May to September. The
fruit is usually paired, cylindrical follicles up to 240 mm long.
The seeds are brown with a tuft of silky hairs.
The impala lily is on the Red Data lists of Swaziland, Zambia and
Zimbabwe where it is regarded as threatened. Most of its distributional
range in South Africa falls within the Kruger National Park where
it is protected, although it does not have any threatened status
in South Africa. The main threats to the species are collection
for horticulture, medicinal use, agriculture and browsing by wild
animals. Baboons, for example, have been seen uprooting whole plants
to feed on the tuberous rootstock.
Distribution and Habitat
The natural distribution range of Adenium multiflorum extends
from southeastern Zambia, through Malawi, Zimbabwe and Mozambique,
to Limpopo, Mpumalanga and the northern parts of KwaZulu-Natal in
South Africa, and Swaziland. These plants are usually found in sandy
soil or in alluvium in rocky habitats, in dry woodland or open grassland,
on brackish flats. They are found mainly in frost-free areas of
the lowveld and eastern parts of southern Africa, south of the Zambezi
River, from sea level to elevations of up to 1 200 m. Although A.
multiflorum grows only in the extreme eastern parts of South
Africa, it is widely distributed in the central and eastern parts
Derivation of name and historical aspects
J.J. Roemer and J.A. Schultes established the genus Adenium
in 1819; up to 12 species have been described in it. In the most
recent revision by Plazier, only five species are recognized. The
genus name is derived from the vernacular name for Adenium obesum,
namely Oddaeyn, or from Aden, where A. obesum was
first collected. J.F. Klotzsch described A. multiflorum in
1861 from material collected in Mozambique. The Latin specific epithet
refers to the multitude of flowers produced by this plant. In earlier
revisions, L.E. Codd considered A. multiflorum as a variety
and G.D. Rowley as a subspecies of a very closely related but more
northerly distributed species, A. obesum. In the latest revision,
it was raised to species level again.
The three other species of Adenium that are found naturally
in southern Africa are A. boehmianum, A. oleifolium and A.
swazicum. A. boehmianum occurs in the northern parts of Namibia.
A swazicum, a much smaller plant that flowers in summer and
has usually pinkish flowers, is found in Mpumalanga and Swaziland.
A. oleifolium grows in Limpopo, Northern Cape, Namibia and
Botswana. All three are cultivated to some extent.
Plants are found in various habitats. Where browsed extensively
they tend to be small and shrubby. In protected areas, however,
they can become handsome trees. The plant has thick, tuberous underground
stems, helping it to survive long periods without water. In nature
the plants propagate by means of seed, which are adapted for wind
dispersal by having tufts of silky hairs.
The impala lily is known in Africa and southern Africa as a source
of fish poison and arrow poison. The poison is prepared from latex
in the bark and fleshy parts of the trunk, but it is always used
in combination with other poisons. Leaves and flowers are poisonous
to goats and cattle, but the plants are sometimes heavily browsed
and are not considered to be of much toxicological significance.
Despite the toxicity, it is used in medicinal applications and as
Horticulturally, the impala lily is greatly valued for its flowers.
A large plant in full bloom is among the most decorative of all
succulents, and is highly prized in gardens where the climate allows
it to be grown in the open. Adenium multiflorum is planted
extensively in the rest camps of the Kruger National Park, for example.
Growing Adenium multiflorum
multiflorum grows well in warm, well-drained situations where
the soil is sandy. In the garden they are not plants for cold or
damp areas. They are ideal subjects for a dry rockery, giving a
warm colourful display of bright flowers in winter. As container
plants they may be kept in cooler places, but do not water them
when they are dormant and protect the plants against frost.
Plants grow vigorously from seed, but rarely flower until they
are 4 to 5 years old. This taxon is seen in cultivation, but is
a distant second to A. obesum in availability, mainly because
of its slower growth rate and shorter blooming season. At the Shingwedzi
Camp in the Kruger National Park some exceptional specimens can
Water the plants well during hot weather. Keep the potting mix
wet in temperatures of 30º C. Plants require high light intensity
and temperatures of around 30º C, hot weather preferably accompanied
by moderate to high humidity. Plants respond well to regular and
generous fertilizing. Add slow-release fertilizer and micronutrients
to potting mediums. Inadequate watering and feeding are the primary
causes for slow growth in adeniums.
Adeniums must be grown in containers in climates with frost or
cool, wet winters. Dormancy can be detected when water consumption
declines or when the leaves suddenly turn yellow: watering should
then be drastically reduced and stopped when the plants are in full
dormancy. Expanding terminal buds will signal the end of dormancy
and watering can then be increased. Plants need ample root space
for rapid growth. The growth of root-bound plants is greatly inhibited
and plants should therefore frequently be re-potted until they reach
the desired size. The potting mix must provide excellent drainage
and aeration. Over-watering and fertilization combined with inadequate
light or poor air movement may lead to weak, elongated growth. Adeniums
are surprisingly adaptable to cultivation-this adaptation includes
adjusting their growth cycles to match the reversed seasons in the
northern hemisphere (Rowley 1999). Care should be taken to avoid
damage to the fleshy, brittle roots, as when repotting.
Propagation is by seed (the only means in the wild) and vegetative
propagation by cuttings or grafting. Larger plants can be obtained
from nurseries. Cuttings should preferably be tip-cuttings dipped
in a rooting hormone and stuck into a coarse rooting medium and
kept well watered. Grafting is also an effective method and more
reliable than cuttings. Growing from seed is easy-seeds germinate
in about a week at 30º C. Treating seeds with a fungicide before
sowing reduces loss. Seedlings usually grow through the first winter
before obligate dormancy appears.
Adenium multiflorum is susceptible to root rot when watered
too frequently during cool weather or if chronically waterlogged
at any time. The use of a well-drained potting medium will prevent
most problems with rotting. Pests rarely damage adeniums grown outdoors.
Indoors or in containers, mealy bugs, spider mites, aphids and white
flies often infest plants. Use pesticides carefully as adeniums
are sensitive to some.
References and further reading
- Codd, L.E. 1963. Apocynaceae. Flora of southern Africa
26. Botanical Research Institute, Pretoria.
- Court, D. 2000. Succulent flora of southern Africa, revised
edn. Balkema, Rotterdam.
- Dimmit, M.A. 2000. Adenium culture in hot climates or greenhouses.
Asklepios 81: 11-19.
- Dimmit, M.A. & Hanson, C. 1991. The genus Adenium in cultivation.
Part 1: A. obesum and A. multiflorum. Cactus and Succulent
Journal (US) 63: 223-226.
- Germishuizen, G. & Fabian, A. 1997. Wildflowers of northern
South Africa. Fernwood Press, Vlaeberg, Cape Town.
- Golding, J. (ed.). 2002. Southern African plant Red Data Lists.
Southern African Botanical Diversity Network Report No.
14. SABONET, Pretoria.
- Onderstall, J. 1984. Transvaal lowveld and escarpment including
the Kruger National Park. South African Wild Flower Guide
4. Botanical Society of South Africa, Cape Town.
- Palmer, E. & Pitman, N. 1972. Trees of southern Africa,
vol. 3. Struik, Cape Town.
- Pienaar. K. 1992. The South African What flower is that?
Struik, Cape Town.
- Plaizier, A.C. 1980. A revision of Adenium Roem. & Schult.
and of Diplorhynchus Welw. ex Fic. & Hiern (Apocynaceae).
Mededelingen Landbouwhogeschool, Wageningen, Netherlands 80,12:
- Rowley, G. 1999. The Cactus File Handbook 5: Pachypodium
and Adenium. Nuffield Press, Oxford.
- Van der Spuy, U. 1971. South African shrubs and trees for
the garden. Hugh Keartland, Johannesburg.
- Van Wyk, B. & Van Wyk, P. 1997. Field guide to trees
of southern Africa. Struik, Cape Town.
- Van Wyk, B.-E. & Gericke, N. 2000. People's plants: a
guide to useful plants of southern Africa. Briza Publications,
- Van Wyk, B.-E., Van Heerden, F. & Van Oudtshoorn, B. 2002.
Poisonous plants of South Africa. Briza Publications, Pretoria.
Stoffel Petrus Bester
National Herbarium, Pretoria