© Geoff Nichols
The genus Carissa consists of evergreen shrubs and trees,
with handsome, glossy foliage and fragrant, starry-white, jasmine-like
flowers. Ornamental and edible, scarlet to crimson oval fruits are
produced after flowering. Carissas are attractive, ornamental shrubs
and make excellent hedges. In late summer, local inhabitants along
the coastal areas of KwaZulu-Natal often sell the fruit to travellers,
especially Carissa macrocarpa, big num-num (Eng.), grootnoemnoem
(Afr.), Amantungulu (Zulu). C. bispinosa, however,
with much smaller leaves, flowers and fruit, does not have to take
a back seat as far as the taste of the fruit is concerned!
species is only occasionally tree-like (up to 5 m) and is more often
a dense bush or rambling shrub in wooded spots or scrub. It is evergreen
and twiggy, the branches exhibiting a repeated forked pattern. The
plants contain a milky sap and the branches are often hairy. Spines
are once- or twice-forked, rarely single, and are sometimes even
absent. Leaves are opposite, simple, shortly petiolate, ovate, broadly
ovate or ovate-elliptic, with a smooth margin, glossy dark green
above, paler below, with short, thorn-like tips (heart-shaped tapering
to a sharp point).
Flowers are small, white or tinged pink, with a long, slender corolla
tube, sweetly scented and clustered at the tips of twigs. Fruit
are small, ovoid, edible, red berries. The whole fruit, including
the seed, is edible and although the skin is slightly milky, it
has a delicious flavour. It is not uncommon to find fruit and flowers
on the same plant.
Carissa bispinosa is found in wooded areas from the southwestern
parts of the Western Cape along the coastal areas right through
the Eastern Cape, KwaZulu-Natal into Gauteng and the northern provinces.
It also occurs in the eastern Free State, Lesotho, Swaziland, Zimbabwe
and Mozambique extending westwards to Botswana and Namibia and sporadically
further north as far as Kenya. The leaves and thorns in particular,
show marked variation throughout the distribution range.
Derivation of name and historical aspects
The name Carissa is derived from the Indian name for plants
of this genus, which contain a bitter and poisonous glucoside in
the bark called carrisin. The epithet bispinosa is derived
from a Latin word that means two-spined, referring to the forked
spines of the plants. The vernacular name num-num could either be
of Hottentot origin or an example of onomatopoeia expressing the
sound of pleasure at the taste of the juicy little fruit of this
Currently, according to the latest revision of the genus, only
Carissa bispinosa (L.) Desf. ex Brenan is accepted. Two varieties,
namely C. bispinosa var. bispinosa and C. bispinosa
var. acuminata (E.Mey.) Codd, were previously distinguished
in South Africa-the former usually a bushveld and coastal scrub
species and the latter a forest species.
Uses and cultural aspects
produce attractive flowers that may attract birds, insects (especially
butterflies) and even monkeys to your garden. Young plants need
to be sheltered from cold for the first years as a precaution. The
plants need moderate watering and grow in semi-shade to full sun.
They are excellent for windy areas as the plants are wind-resistant.
Plants are moderately drought-resistant but rather frost-tender
and therefore best suited to the warmer parts of the interior and
coastal plains as they are very tolerant of sea breezes.
Num-nums can also form a focal point with their ornamental foliage,
flowers and fruit. Natural environments with frequent fire regimes
result in low-growing forms. These plants have cultivation potential
for use as borders in formal gardens. This species can also be used
to provide neat hedges in parking areas.
Traditionally, the plants are not only used for the edible fruit
but the berries are also used to make jams and jellies. The indigenous
people even use the roots to treat toothache. Carissa bispinosa
is also used in an annual Swazi ceremony, increasing the courage
and ferocity of a black bull when Swazi warriors have to be tested
by killing the bull with their bare hands.
Growing Carissa bispinosa
Carissa bispinosa is a fast-growing, medium-sized, evergreen
shrub. It is obtainable from local nurseries countrywide and is
cultivated extensively. Plants flower mainly from October to March
and produce their edible berries from March to October.
Plants should be spaced approximately a metre apart to form an
impenetrable hedge-they are well armed with thorns. They can also
be used as ornamental plants in an informal border. Carissa bispinosa
should be planted in light, well-drained soil with the addition
of plenty of compost. It can be lightly pruned to keep it neat.
It can easily be cultivated from seed. These plants are of decorative
value because of the contrast in leaves, flowers and fruit. The
shining green leaves complemented by either bright red fruit or
shimmering white flowers and a pleasant scent will be a welcome
addition to any garden. They thrive near the coast or in gardens
inland where winters are mild. They can be grown in gardens that
have moderate frost, but the rate of growth is much slower in areas
where winters are cold.
References and further reading
- Coates Palgrave, M. 2002. Keith Coates Palgrave Trees of
southern Africa, edn 3. Struik, Cape Town.
- Codd, L.E. 1963. Apocynaceae. Flora of southern Africa
26: 250-258. Botanical Research Institute, Pretoria.
- Fabian, A. & Germishuizen, G. 1997. Wildflowers of northern
South Africa. Fernwood Press, Vlaeberg, Cape Town.
- Glen, H.F. 2002. Cultivated plants of southern Africa.
- Joffe, P. 1993. The gardener's guide to South African plants.
Tafelberg, Cape Town.
- Leeuwenberg, A.J.M. & Van Dilst, F.J.H. 2001. Series
of revisions of Apocynaceae XLIX Carissa L. Wageningen University
Papers, Blackhuys Publishers, Leiden, The Netherlands.
- Palmer, E. & Pitman, N. 1972. Trees of southern Africa,
vol. 3. Balkema, Cape Town.
- Pienaar, K. 1992. The South African What flower is that?
Struik, Cape Town.
- Swart, W.J. 1982. Survival off the bush-5: The yummy num-nums.
Farmer's Weekly, October 1982: 58, 59.
- Van Der Spuy, U. 1971. South African shrubs and trees for
the garden. Hugh Keartland, Johannesburg.
- Van Wyk, B.-E. & Gericke, N. 2000. People's plants: a
guide to useful plants of southern Africa. Briza, Pretoria.
- Walker, J. 1996. Wildflowers of KwaZulu-Natal. Interpak,
Stoffel Petrus Bester
National Herbarium Pretoria