The Portulacaria afra is an incredibly versatile and resilient succulent plant, revered in its native Southern Africa not only for its medicinal and nutritional value but also for its globally significant ecological benefits, particularly its unique ability to sequester atmospheric carbon dioxide. It is commonly known as the Elephant Bush or the legendary Spekboom.
Herb's Introduction
The subject of this comprehensive review is Portulacaria afra Jacq., a robust and multi-faceted small-leaved succulent. Belonging to the Family Didiereaceae, this plant is a soft-wooded, semi-evergreen shrub or small tree native to the arid and semi-arid regions of Southern and Eastern Africa, particularly prolific in South Africa’s Eastern Cape. It is a keystone species in the Albany Thicket vegetation, playing a critical role in the local ecosystem. While often grown globally as a popular ornamental houseplant and bonsai specimen due to its attractive appearance and ease of care, its true fame lies in its unparalleled environmental role as an exceptional "carbon sponge." The plant achieves this remarkable feat by utilizing a specialized dual-pathway photosynthesis mechanism, allowing it to efficiently absorb and process carbon from the atmosphere even under harsh, drought-stricken conditions where most other flora would cease activity. This botanical marvel has long been utilized by indigenous communities for sustenance and traditional healing, cementing its status as one of Africa's most important indigenous plants.
Name in Different Countries
Portulacaria afra has amassed a variety of common names worldwide, reflecting its distinctive appearance, traditional consumption, and its natural inhabitants. Language / Region Name Meaning / Context English (Global) Elephant Bush Named because it forms a favorite food source for elephants, who browse the leaves and small branches. English (Global) Porkbush A traditional name linked to its historical use as fodder for livestock, especially goats and domestic stock. English (Global) Dwarf Jade / Miniature Jade A popular name due to its striking resemblance to the Jade Plant (Crassula ovata), though it is not closely related and has smaller leaves. Afrikaans (South Africa) Spekboom Directly translates to "Bacon Tree" or "Pork Tree," again referencing its use as fodder for livestock. Arabic رجلة الصبار (Rijlat al-Sabbar) Loosely translating to "Purslane Cactus," referencing its succulent nature and link to the Purslane plant family. Chinese 樹馬齒莧 (Shù mǎchǐxiàn) Meaning "Tree Purslane," acknowledging its tree-like growth habit and its former classification. Finnish Pensasportulakka Meaning "Bush Purslane," also reflecting its shape and classification. Persian پورتولاکاریا افرا (Purtulākāriyā Afrā) A transliteration of the scientific name. Export to Sheets
Terminology
Scientific Name: Portulacaria afra Jacq. Genus (Portulacaria): Derived from the genus Portulaca (Purslane) and the Latin suffix '-arius,' meaning "pertaining to," due to its superficial similarity to Purslane plants. Specific Epithet (afra): A direct reference to its origin, signifying "from Africa." Family: Didiereaceae While historically classified in the family Portulacaceae, recent molecular phylogenetic studies have firmly placed Portulacaria afra within the Didiereaceae family, which is otherwise largely endemic to Madagascar. This reclassification highlights its unique evolutionary path. Synonyms: The extensive list of synonyms, including Crassula portulacaria L., shows the historical confusion regarding its classification, often linking it to the Jade Plant genus (Crassula) before its correct placement. Dual Photosynthesis (CAM): The plant’s ecological significance is rooted in its biochemical terminology. It has the rare capacity to switch between two photosynthetic pathways: C3 (used by most plants in favorable conditions) and Crassulacean Acid Metabolism (CAM). The CAM pathway allows the plant to absorb CO₂ during the cool night, minimizing water loss during the hot, dry day—a critical adaptation that makes it a highly efficient "carbon sponge" in arid environments.
Availability
Portulacaria afra is widely available both in its natural habitat and globally through horticulture. Native Distribution: The plant is naturally found across the eastern parts of South Africa, stretching from the Eastern Cape, through KwaZulu-Natal, Mpumalanga, and Limpopo Province, and extending north into Eswatini and Mozambique, and as far as Kenya in Eastern tropical Africa. It is a resilient native in warm situations on rocky slopes, in thicket, bushveld, and succulent karoo scrub, often dominating the landscape known as Spekboomveld. Cultivation and Global Market: It is exceptionally popular worldwide and is readily available in plant nurseries and garden centers, typically sold under the common names Elephant Bush or Dwarf Jade. Hardiness: It is a frost-tender plant, hardy outdoors only in USDA Hardiness Zones 9 to 11. In cooler climates, it is cultivated exclusively as a low-maintenance houseplant or seasonal outdoor container plant. Varieties: Numerous cultivars exist and are available in the market, including the sprawling groundcover form ('Prostrata'), the large-leafed variety ('Limpopo'), and popular variegated forms ('Foliis variegatus' or 'Rainbow Bush'), offering different aesthetic appeals. Ecological Availability: Large tracts of P. afra are being utilized and restored in South Africa for significant ecological projects aimed at carbon sequestration and reversing land degradation, making it a key species in environmental availability programs.
External Look
Portulacaria afra is characterized by a distinctive, robust, yet delicate appearance, leading to its popular use in ornamental settings. Size and Habit: It is a soft-wooded, semi-evergreen upright shrub or small tree. In its native environment, it commonly reaches heights of 2.5–4.5 meters (8–15 feet), but can grow up to 6 meters (20 feet) tall under ideal conditions. When grown in cultivation as a container plant or bonsai, its size is easily managed and kept much smaller, often just 0.5 to 1 meter tall. Stems and Branches: The plant features brittle, fleshy, and flexible tapering branches. Young stems are often a vibrant reddish-brown color, providing a striking contrast against the green foliage. As the plant matures, the main trunk and woody stems thicken and develop a grayish-brown, somewhat textured bark. Leaves (Pads): The foliage is its defining characteristic. The leaves are small (typically 1/2 to 3/4 inch long), nearly sessile (without a distinct stalk), glossy emerald green, and distinctly round to oval in shape. They are highly succulent, meaning they are plump and store large amounts of water, contributing to the plant's remarkable drought tolerance. Distinction from Jade Plant: Although often mistaken for the Jade Plant (Crassula ovata), P. afra has smaller, rounder, and softer leaves, shorter internodal spaces (giving it a more compact growth), and more limber, tapering branches. Flowers and Fruit: While rare in cultivation, established outdoor plants may produce a profusion of tiny, star-shaped pink or pale white flowers in clusters at the ends of the branches, typically in late spring or early summer after a dry winter. These are followed by small, transparent, berry-like dry fruits.
Healing Properties
The Elephant Bush has been a staple in traditional African herbal medicine for centuries, with its healing properties attributed to a rich profile of secondary plant metabolites, including polyphenols, alkaloids, and terpenoids. Scientific studies have validated many of these traditional uses, confirming its potent pharmacological activities. Antiseptic and Wound Healing: The leaf juice and crushed leaves are widely used as a topical antiseptic. They are applied directly to sores, chronic wounds, blisters, corns, and insect stings to prevent infection and promote rapid healing. Anti-inflammatory and Analgesic: Crude extracts have demonstrated significant anti-inflammatory and analgesic (pain-relieving) properties. Traditionally, a leaf decoction is applied topically for pain and inflammation, and the leaves are chewed to soothe mouth ulcers and sore throats. Skin Ailments: The astringent juice is a popular remedy for a variety of skin conditions, including rashes, pimples, sunburn, and other skin spots and irritations, providing a cooling and soothing effect. Metabolic and Systemic Support: Orally administered leaf decoctions have been used by traditional healers to manage several internal systemic ailments, including diabetes, hypertension, fever, kidney ailments, diarrhea, and stomach ailments. Research supports its antidiabetic potential, showing activity related to glucose utilization. Respiratory Relief: Decoctions are also used as a traditional remedy for respiratory infections, tonsillitis, and tuberculosis. Hydration and Exhaustion: Chewing and sucking on the leaves provides immediate hydration and is a recognized traditional method to combat dehydration, heatstroke, and over-exhaustion due to the high water content and mildly acidic, refreshing taste. Lactation: It is traditionally used as a galactagogue, with leaf decoctions taken orally to increase breast milk production in lactating mothers.
Advantages
The advantages of Portulacaria afra extend far beyond its use as a simple ornamental or medicinal plant, highlighting its critical role in climate mitigation and environmental sustainability. 1. Carbon Sequestration (The “Carbon Sponge”) This is arguably the plant’s most globally significant advantage. P. afra is one of the most efficient carbon absorbers in the plant kingdom. Dual Photosynthesis Pathway: Its ability to switch to Crassulacean Acid Metabolism (CAM) during dry, hot periods allows it to continue photosynthesizing and sequestering carbon when other plants shut down. High Absorption Rate: A stand of Spekboom in arid thicket has the capability to remove more carbon from the atmosphere than an equivalent amount of deciduous forest, making it a key tool in fighting climate change. 2. Resilience and Ecological Stability Drought, Heat, and Fire Resistance: It is exceptionally tolerant of heat and prolonged drought due to its succulent leaves and water-storing capacity. Furthermore, it is naturally fire-resistant, crucial for ecological stability in dry regions. Soil and Ecosystem Enhancement: It acts as an excellent soil binder, helping to prevent soil erosion. The spreading shrub covers and shades the ground, creating a micro-climate that improves water-holding capacity and enriches the soil with organic matter, thus supporting other plants and micro-organisms. 3. Nutritional and Edible Value High in Nutrients: The leaves are edible and highly nutritious, being notably rich in Ascorbic Acid (Vitamin C), which is beneficial for the immune system. Low in Fat and Sugar: The leaves have a low content of sugar, fat, and protein, making them a healthy, hydrating dietary supplement. 4. Cultivation and Versatility Easy Propagation: It is extremely easy to propagate from stem cuttings, allowing for rapid spreading and restoration projects. Non-Toxic: Unlike the similar-looking Jade Plant (Crassula ovata), P. afra is generally considered non-toxic to humans and pets.
Uses
The uses of Portulacaria afra are diverse, spanning the culinary, medicinal, ornamental, and ecological fields. Culinary Use (Edible Leaves): The fleshy leaves have a pleasant, slightly tart or sour flavor due to their high malic acid content. They are commonly eaten raw, used to add a refreshing, zesty crunch to salads. They are also incorporated into traditional stews, sauces, and soups, particularly in South African cuisine. Historically, they served as a vital famine food and an immediate source of water. Traditional and Modern Medicine: Used extensively in traditional Southern African medicine (as detailed in the "Healing Properties" section) for topical applications (wounds, stings, rashes) and oral consumption (diabetes, respiratory issues). Ecological and Environmental Restoration: Large-scale carbon farming and environmental initiatives utilize Spekboom for rapid CO₂ absorption. It is used in soil conservation and restoration projects to rehabilitate degraded land, stabilize soil, and re-establish a healthy ecosystem. Horticultural and Ornamental Use: Houseplant: A popular indoor plant due to its hardiness and attractive appearance. Bonsai: The plant is a favorite subject for bonsai enthusiasts, as its woody stems can be easily manipulated and pruned, and it develops a striking, gnarled trunk with age. Xeriscaping/Landscaping: Used as a drought-tolerant ornamental shrub, screen, hedge, or groundcover (using the 'Prostrata' form) in warm, arid garden designs. Fodder: It remains an essential food source (fodder) for wildlife, including elephants, rhinoceros, and tortoises, and is crucial for grazing livestock, especially during periods of drought.
Using way
The application of Portulacaria afra depends on its intended use—medicinal, culinary, or cultivation. 1. Medicinal/Traditional Application For Wounds, Blisters, Insect Stings, and Skin Rashes: Crush several fresh leaves between your fingers to extract the sap/juice. Apply the juice or the macerated leaf material directly to the affected area as an immediate antiseptic and soothing poultice. For Dehydration, Heatstroke, and Mouth Ulcers: Chew and suck on one or two fresh, cleaned leaves. The high water content and slightly sour taste will help quench thirst and provide relief to mucous membranes. For Internal Ailments (Traditional Decoction): Leaves are boiled in water to create a decoction (tea) that is consumed orally to treat symptoms of fever, stomach ailments, and hypertension (always consult a medical professional before using herbal remedies for serious conditions). 2. Culinary Application Salads: Harvest the small, round, fresh leaves and wash thoroughly. Chop or simply sprinkle them whole onto salads for a citrusy, tart crunch. The leaves are generally considered to have the most acidic flavor when harvested during the day. Stews/Soups: Add the leaves to cooking dishes towards the end of the cooking process to preserve their slight crunch and tart flavor, where they act similarly to sorrel. 3. Cultivation and Care Sunlight: Thrives in full sun (at least 6 hours) outdoors. Indoors, place it in the brightest location possible, ideally a south-facing window, ensuring it receives bright, indirect light to prevent stretching. Soil: Requires extremely well-draining soil. A specialized cactus and succulent potting mix, often cut with perlite, pumice, or grit, is necessary to prevent root rot. Watering: Follow the “soak and dry” method. Water deeply only when the soil has completely dried out, especially during the growing season (spring/summer). In winter, when the plant is dormant, significantly reduce or cease watering. The leaves will wrinkle slightly when thirsty. Propagation: The easiest method is by stem cuttings. Simply cut a branch, allow the cut end to dry and form a callus for a few days, and then place it in dry, well-draining soil. Roots will often form quickly. Frost: Must be protected from frost. Bring container-grown plants indoors when temperatures are consistently near 40°F (4°C) or lower.
Conclusion
Portulacaria afra, the Spekboom or Elephant Bush, is a plant of extraordinary value. From its identity as a life-sustaining food source for elephants and a traditional medicine chest for indigenous peoples, to its contemporary importance as a sought-after ornamental and bonsai subject, its utility is immense. Crucially, its unique physiological ability to absorb massive amounts of atmospheric carbon dioxide positions it as a vital biological resource in global efforts to mitigate climate change and restore degraded lands. Highly resilient, low-maintenance, nutritious, and medicinal, this African succulent stands as a powerful symbol of ecological toughness and a testament to the untapped potential of indigenous flora, earning its designation as a keystone species for a healthier planet.
