General Info – summary

This Tree is up to 5m high or a much-branched shrub.  Distinctive paired, Y-shaped equal spines are up to 4,5 cm long.  Non-toxic milky latex is present.  Evergreen, leathery, hairless, simple Leaves are mucronate. Bisexual, actinomorphic, 5-merous white Flowers have a corolla + tubular base & imbricated lobes. Apiculate anthers don’t protrude beyond the mouth.  Ovary is superior.  Edible Fruit is a fleshy berry.

Description

Carissa macrocarpa

Previous Names: Ardunia macrocarpa, Carissa grandiflora.

SA Tree No. 640.3.

Common names: (Afr) Amatoengoela, Amatungula, Groot Noem-noem, Grootnoem-noem.  (Eng) Amatungulu, Big Num-num, Large Num-num, Natal plum.  (isiXhosa) Nmthungulu.  (isiZulu) Amathungulu, Umthungulu.  (siSwati) Umthungulu.

Family Apocynaceae (Oleander or impala lily: Adenium multiflorum family).  This family includes the exotic genera Oleander and Plumeria (Frangipani).  Indigenous genera containing trees on this site include Acokanthera, Adenium, Carissa, Rauvolfia and Tabernaemontana.  Currently the family has 366 genera and in excess of 5 000 species.  In South Africa, there are 90 genera and about 700 species.  All have milky or clear sap.  The simple, entire and pinnately veined Leaves are usually opposite and may have stipules situated between the petiole and the stem.  The Inflorescence is usually a cyme (a broad, more or less flat-topped, determinate flower cluster, with central flowers opening first).  The regular and bisexual Flowers are usually bracteate.  The Calyx has 4-5, usually free sepals and the 4-5 Petals are joined – at least at the base of the staminal column.  A corona (an extension) is often present either on the corolla or arising from the base of the staminal column.  The 4-5 Stamens are variously located and have anthers with 2 pollen sacs.  The superior to half-inferior Ovary has 2 carpels.  Fruit is various.  The often-compressed Seeds may have a tuft of silky hair at the micropylar end.  The micropyle (a small opening in the surface of an ovule, through which the pollen tube penetrates, is often visible as a small pore in the ripe seed.  During germination, the seedling’s radicle – embryonic root – emerges through the micropyle).

Name derivation: Carissa from Corissa – the name given to an Indian species of the same genus.  It is derived from Sanskrit (primary sacred language of Hinduism).  macrocarpa – refers to the large fruit (Greek).

Conservation: National Status: L C. (Least Concern).  Assessed: Raimondo et al. (2009).

Tree

This small evergreen Tree is up to 5m high and is usually about the same width (photo 442).  It is usually a densely twiggy, much-branched, shrub.  All parts may exude latex that is white, milky and non-toxic.  Young stems are green (photo 440).  The older grey/brown rough Bark becomes wrinkled into longitudinal ridges or channels (photo 441).  Woody, strong and sharp Spines are once or twice forked (photo 893).   These paired spines have the same length.  They are Y-shaped, opposite, rigid and may initially be red tipped (photo 893).  Spines initially arise at the tip of a shoot and each spine is up to 4,5cm long.  These persistent spines are still visible on older branches (photo 570).

Leaves

This evergreen plant has leathery, hairless Leaves that are simple (has a single blade which may have incisions that are not deep enough to divide the blade into leaflets).  The leaves are broadly ovate (egg-shaped – photo 409), obovate (photo 150) or oval to almost round and up to 7 x 5cm.  The slightly rolled under Margin is entire (with a continuous margin, not in any way indented) and the Petiole (leaf stalk) is up to 5mm long and grooved on top (photo 409).  In this recently removed leaf, the harmless white latex is visible.  This is unlike the very toxic latex present in species of Acokanthera (in the same family).  Lateral veins may protrude slightly above (photo 409).  The Midrib (the main rib of a leaf or leaf-like part, a continuation of the petiole) protrudes below.  Leaves are shiny dark green above and lighter below (photo 409).  New leaves are a copper colour (photo 895).  The Apex is tapering to rather rounded or sharply mucronate (ending abruptly with a distinct hair like tip – photo 409).  The Base is square, rounded or tapering.  Axillary glands are conspicuous.

Flowers

The conspicuous white, 5-merous (in parts of 5’s) Flowers may be tinged with pink (photo 366 & 369 + the exterior views of new and mature petals).  Flowers are visible most of the year and are up to 3,5cm wide and solitary, in terminal clusters or at spine bases (photo 369).  They have a scent that tends to be stronger at night – similar to orange blossoms and are actinomorphic (Regular, symmetrical.  Flowers are vertically divisible into similar halves by more than 1 plane passing through the axis).  The small green Calyx is 5-lobed (photo 366) and imbricate (having regularly arranged, overlapping edges – photo 568).  The Corolla is gamopetalous (united; joined petals at least at the base) and tubular (photo 369).  The tube is up to 1,4cm long (dissected in photo 408).  From this tube, the 5 spreading lobes extend laterally.  Each is up to 3,1cm long the bases of the lobes are imbricate – (overlapping on one side – photo 367).  As a result, a picked flower will rotate, if carefully held then blown from the top.  Flowers may develop close to the Y-shaped spines (photo 366), or terminally.  They may also be in small clusters.  The 5 Stamens are attached to, and alternate with the petals but do not protrude above the corolla tube (photo 408).  They are epipetalous (borne on or arising from the corolla petals).  The Filaments (the slender stalk that supports the anther) are short, slender, and the Anthers are 4-locular and apiculate (ending in a short, sharp, flexible point – photo 408).  No Disc (a more or less fleshy or elevated development of the receptacle) is present.  There is a single Pistil (a unit of the Gynoecium, the female element of the flower, composed of the Ovary, Style and Stigma) and the entire flower is hypogenous. Here the perianth (calyx and corolla) and stamens are attached to the receptacle below the receptacle (the expanded tip of the pedicel (flower stalk) from which the floral parts develop).  The Ovary is thus superior.

Fruit

The large, ovoid, fleshy Fruit is a thin-skinned Berry (pulpy, indehiscent fruit like a grape or tomato) that is up to 5 x 3,5cm.  The initially green fruit (photo 439) with a pointed tip, matures to a red colour (photo 845) and may have a white bloom (photo 438).  The fruit contains up to 4 thin, flat and oval to irregularly shaped Seeds (photo 848).  (Sep-Mar).

Distribution & Ecology

This fast-growing plant is resistant to wind and sea-spray.  It is common and often conspicuous in severe frost-free coastal areas including dunes and coastal forests and usually grows below 500m.  The plant is cold (to -5°C), and drought resistant.  In South Africa it occurs close to the coast occurring naturally in the Eastern Cape and KwaZulu-Natal. Beyond South Africa it occurs up the coast of Mozambique – up to as Angoche (about three-quarters the way up the coast).   Trees also occur in warmer northern areas like Zambia, Zimbabwe, Kenya and the Congo.  The Fruit attracts many animals, including birds and monkeys.  Pollination is by small beetles, hawk moths and other night-flying insects.  Hawk moths (named because of their swift flight patterns) have a long flexible proboscis (in insects – elongated sucking mouthpart that is typically tubular, flexible and coils up when not in use).  The proboscis is use in nectar feeding and aids pollination.

Ethnobotany

The whole Fruit is edible and tasty.  The red flesh is tender and very juicy.  It is rich in vitamin C, and also contains magnesium, phosphorus and calcium and makes an excellent jam.  One hectare of land can produce up to 3 tons of fruit annually.  It grows easily from cuttings, which are initially slightly frost sensitive.  Seeds can be used for propagation, but the cuttings are more successful.  It is suggested that notching young branches, bending them down and leaving them in soil for 2 months will cause them to sprout.  Thereafter it is planted in sand.  Rooting should occur within a month.  This plant can survive without fertilizer.  Carissa macrocarpa has now been planted in Miami, Florida, California, Hawaii, Bahamas, Philippines, India, East Africa and Israel.  It is also valued as a protective and ornamental hedge that can tolerates both salt spray and wind.  Pruning causes more flower and fruit development.

References

Boon, R. 2010. Pooley’s Trees of eastern South Africa. Flora and Fauna Publications Trust, Durban.

Burrows, J.E., Burrows, S.M., Lotter, M.C. & Schmidt, E. 2018. Trees and Shrubs Mozambique.  Publishing Print Matters (Pty) Ltd.  Noordhoek, Cape Town.

Coates Palgrave, M. 2002. Keith Coates Palgrave Trees of Southern Africa, edn 3. Struik, Cape Town.

Lawrence, G. H. M, 1951. Taxonomy of Vascular Plants. The Macmillan Company, New York. Tenth Printing 1965.

Palmer, E. & Pitman, N. 1972. Trees of southern Africa. Balkema, Amsterdam, Cape Town.

van Wyk, B. & van Wyk, P. 1997 Field guide to Trees of Southern Africa. Struik, Cape Town.

von Staden, L. 2018. Carissa macrocarpa (Eckl.) A.DC. National Assessment: Red List of South African Plants version . Accessed on 2024/10/03.

 

https://en.wikipedia.org/wiki/Carissa_macrocarpa

https://hort.purdue.edu/newcrop/morton/carissa.html

http://www.plantzafrica.com/plantcd/carismac.htm

http://posa.sanbi.org/flora/browse.php?src=SP