The Num Num plant, formally known as Carissa macrocarpa, is a robust, evergreen shrub native to the warm, coastal regions of Africa. It is widely recognized under the common names Natal Plum and Large Num Num. This hardy species is prized both as a dense, thorny landscape shrub and for the distinctive fruit it produces. It belongs to the Apocynaceae family, which typically includes species known for possessing milky sap.
Native Habitat and Primary Distribution
The indigenous range of Carissa macrocarpa is concentrated along the eastern coastline of Southern Africa. Its natural distribution extends from the Eastern Cape province of South Africa northward through KwaZulu-Natal and into Mozambique. The plant is adapted to the harsh conditions of this region, thriving in coastal bush, scrub forests, and on seaside sand dunes. This native environment has instilled in the shrub a high tolerance for salt spray and strong winds. Its primary distribution extends further inland and north into parts of Zambia, Zimbabwe, and the Democratic Republic of the Congo.
Global Cultivation and Ornamental Presence
Beyond its native grounds, the Num Num plant is cultivated across warm, frost-free regions globally. It is widely used as a landscape shrub in the United States, particularly in the subtropical climates of Southern California and Florida. The plant’s dense growth habit and stout, forked thorns make it a popular choice for creating impenetrable security hedges and barriers.
Its tolerance for poor soils and low water requirements has made it a valuable ornamental plant in areas with water restrictions. Cultivation is common in other warm regions, including Hawaii, parts of Central America, the Caribbean, and subtropical areas of Australia and New Zealand. The shrub’s ability to withstand salt-laden winds makes it an excellent choice for landscaping near the ocean. In some areas, such as South Florida, it has become naturalized and is considered an emerging invasive species due to its hardiness.
Identifying Features and Edibility
Carissa macrocarpa is identified by its characteristic morphological features. It produces thick, leathery leaves that are glossy, dark green and arranged oppositely along the stems. A distinct feature is the presence of stout, double-pronged thorns, which are typically found in pairs and can reach up to two inches in length.
The plant produces delicate, star-shaped flowers that are pure white and highly fragrant, with a scent often compared to orange blossoms. Following pollination, the plant yields the edible fruit, which is oval-shaped and changes from a milky green to a vibrant reddish-purple or crimson when fully ripe. The ripe fruit, the “Num Num,” is plum-like in appearance and contains small, flat brown seeds embedded in its juicy flesh.
While the ripe fruit is safe for consumption and often used to make jams, pies, and sauces, caution must be observed regarding the rest of the plant. All other parts of the shrub, including the leaves, stems, and unripe fruit, contain a white, sticky latex or sap. This milky substance is mildly toxic and should not be ingested, as consuming it can lead to gastrointestinal distress. Ripeness is the only reliable indicator of edibility, as the latex content significantly decreases when the fruit darkens to its final color.