African Milkbush, Pencil Cactus, Milk Bush
Euphorbia tirucalli

Family: Euphorbiaceae

What it is like

Other common names include Pencil Cactus, Milk Bush, Pencil Euphorbia, and Rubber Hedge Euphorbia. Euphorbia tirucalli or commonly known as African Milkbush is a succulent shrub or small tree about 12 m in height. It has high toxicity but is harvested from the wild for medicinal purposes. Young branches can be roasted then chewed to relieve sore throat while the ash from burning the branches can be used against cough and open abscesses. The pulped twigs are applied externally for leg oedema. Broken bones can be treated using poultices from the stem. Different forms and preparations of plant parts can also be used against ulceration of nose, haemorrhoids, swellings, gonorrhoea, schistosomiasis, snake bites, stomach pain, constipation, intestinal worms, headache, asthma, epilepsy, vomiting, etc. African Milkbush is highly tolerant to salinity and drought and can be converted to biofuels. It is planted to protect sand dunes and care soil in dry areas from wind and water erosions. The wood is used for fuel, toys, rafters, and veneers.

Euphorbia tirucalli is an evergreen Shrub growing to 5 m (16ft) by 5 m (16ft) at a slow rate. See above for USDA hardiness. It is hardy to UK zone 10 and is frost tender. The flowers are pollinated by Insects. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very acid, very alkaline and saline soils. It can grow in semi-shade (light woodland) or no shade. It prefers dry or moist soil and can tolerate drought. The plant can tolerates strong winds but not maritime exposure.

Height (m): 5

Where it is found

Normally found in dry bushland thickets and naturalizes easily in brushwood, open woodland and grassland at elevations up to 2,000 metres.

Dry regions of tropical Africa, though widely grown and naturalised in many areas of the tropics.

Conservation Status: Status: Least Concern

Countries/locations it is found in

Angola; Congo, The Democratic Republic of the; Madagascar; Mozambique; Rwanda; South Africa; Swaziland; Tanzania, United Republic of; Zambia, Africa, Angola, Arabia, Asia, Botswana, Central Africa, East Africa, Ethiopia, Haiti, India, Madagascar, Malawi, Mozambique, Pakistan, Southern Africa, Sri Lanka, Sudan, Zambia, Zimbabwe,

How it is used

Food

Rating: 0

Possible? but currently no data

Medicine

Rating: 2

Caution should be observed in making medicinal preparations of this plant due to its high toxicity. Anecdotal evidence suggests that the risks of a lethal overdose are high, particularly when treating children. Various studies have shown the presence of a range of active compounds in the plant: Euphorbon, which is isolated from the needles, contains 4% caoutchouc. The latex yielded 75 to 82 percent resin, and 14 to 15 percent caoutchouc. The latex is rich in terpenes, including ingenol and phorbol esters. The latter, which is highly irritating, has been shown to be tumour-promoting. Six terpenes have been isolated from the plant: cyclotirucaneol; cycloeuphordenol; tirucalicine; tirucaligine; euphorginol; and euphorcinol. The latex showed great similarity in composition and activity to the highly poisonous croton seed oil from Croton tiglium. The young branches can be roasted then chewed to relieve a sore throat. Ash from the burned branches and stems is used to treat whooping cough. The pulped twigs are applied externally to treat oedema of the legs. Ash from the burned branches and stems is applied externally as a caustic to treat open abscesses. Poultices from the stem are applied to heal broken bones. Based on the Theory of Signatures, the jointed nature of the plant-stems lead to the use of the plant in SE Asia in a belief that it will assist the healing of broken bones. A root and bud decoction is taken as a laxative, and to treat coughs and pectoral pain. A poultice of the roots or stems has been applied to ulceration of the nose, haemorrhoids and swellings. A root-decoction, combined with other drug-plants, is taken in in the treatment of schistosomiasis and gonorrhoea. The boiled root juice acts as an emetic in cases of snake bite, and is also used for sterility in women. Heated root scrapings, mixed with coconut oil, are applied externally to the stomach to relieve stomach-ache. The caustic latex is vesicant, rubefacient and counter irritant. It is purgative in small doses, emetic in larger quantities. Two or three drops at a time are given to adults with their food, whilst a dose of 3 - 4 drops is used as a purge to treat ascites and generalised oedemas. The potent purgative and emetic properties are employed in Africa in order to treat stomach complaints, constipation, intestinal worms, headache, asthma, epilepsy and palpitations. A few drops of latex are reportedly sufficient to cause vomiting, and are taken in milk as an antidote to poisoning or snakebites. Heated branches are chewed and the latex is swallowed to relieve a sore throat and dry cough, but also to induce labour during childbirth. The latex is taken in the treatment of sexual impotence and sterility in East Africa, and elsewhere as a sexual stimulant. It is also said to promote breast enlargement. The latex is used externally to treat skin-complaints, itches, insect bites, rheumatism, toothache, earache, to raise blisters on syphilitic nodes, and to remove warts, tumours, cancers, etc. It is also used for wound healing. The latex is widely used in Brazil to treat cancer, but in some areas where it is commonly used, tumours of the nose are prevalent and thought to be related to this use.

Antiasthmatic: Treats asthma.

Antidote: Counters poisoning.

Antihaemorrhoidal: Treats haemorrhoids (piles). This would probably be best added to another heading.

Antirheumatic: Treats rheumatism.

Antitumor: Preventing, or effective against, tumors, it is used in the treatment of cancer. Probably synonymous with Cytotoxic.

Cancer: Used in the treatment of cancer.

Emetic: Induces vomiting.

Epilepsy: Used in the treatment of Epilepsy - a disorder in which nerve cell activity in the brain is disturbed, causing seizures.

Laxative: Stimulates bowel movements in a fairly gentle manner.

Odontalgic: Treats toothache (temporary measure only) and other problems of the teeth and gums.

Parasiticide: Treats external parasites such as ringworm This should perhaps be joined with Parasiticide in

Poultice: A moist, usually warm or hot, mass of plant material applied to the skin in the treatment of burns etc.

Purgative: A drastic laxative causing a cleansing or watery evacuation of the bowels, usually with a griping pain.

Rubefacient: A counter-irritant and external stimulant, it produces inflammation and redness of the skin.

Skin: Plants used in miscellaneous treatments for the skin.

Stimulant: Excites or quickens activity of the physiological processes. Faster acting than a tonic but differing from a narcotic in that it does not give a false sense of well-being.

Stings: Used in the treatment of stings and insect bites.

Vesicant: A blistering agent.

Other

Rating: 4

Seaside, Small flowering tree/shrub, Accent, Large planter, Bonsai, Civic centre, Xerophytic. Agroforestry Uses: It is planted to protect sand dunes and bare soil in dry areas from wind and water erosion. E. Tirucalli fences can act as erosion breaks. It is unsuitable for intercropping since it suppresses undergrowth, including crops. An effective plant for land reclamation programmes, it is very drought resistant and efficient in photosynthesis because of its unique photosynthetic physiology combining both the Crassulacean acid metabolism and the C3 pathways. During humid spells when leaves are present, this combination allows high CO2 uptake and, thus, elevated growth rates. Plantations have succeeded in some instances at more than 5,000 ppm in arsenic mine spoil mounds. An extensively used hedge plant in rural areas of East Africa. Its dense growth and caustic, irritant sap combine to make an effective deterrent to small animals and human marauders from forcing a passage. The latex must also protect it from browsing animals though sheep and the omnivorous goat are said to eat it in some areas. The hedge can be easily established with cuttings planted in situ. Other Uses: A potential biomass crop. Its use as a source of hydrocarbons has been investigated by a number of authors, the latex hydrocarbon is largely a C30 triterpenoid which on cracking yields high octane gasoline. It is estimated that 1-2 t of crude oil can be obtained per ha per year from E. Tirucalli. The gross energy value of E. Tirucalli biomass is 17 600 kJ/kg. The biomass can be converted into gas, liquid fuels and solid fuels such as pellets, briquettes and charcoal. The sap evidently has strong fixative power: mixed with animal hair it is used for fastening knife-blades to wood handles and spear-heads to shafts. The latex is piscicidal and insecticidal. It showed strong activity against Colletotrichum capsici, Fusarium pallidoroseum, Botryodiplodia theobromae, Alternaria alternata, Penicillium citrinum, Phomopsis caricae-papayae and Aspergillus niger. The latex is highly toxic to the parasitic nematodes. Hoplolaimus indicus, Helicotylenchus indicus and Tylenchus filiformis. The plant is also used as an effective repellent for mosquitoes and ants. The latex is an emulsion of about 30% (principally euphol) terpenes in water. During the Second World War the latex was used in South Africa in the development of a rubber substitute, but this proved to be unstable and unprofitable due to the high latex resin content. Euphorbia latex contains a mixture of light hydrocarbons of molecular weight around 20,000, and after removal of the water the residue is a liquid oil. Triterpenic alcohols have also been identified in the latex. A form of rubber is obtained from the latex which contains a high proportion of resin: 14.3 - 15.7% caoutchouc, 75.8 - 82.1% resin, dry weight, in material from S Africa. The resin can be used in varnishes for certain purposes in the absence of better materials, but only at a high cost. Steam-distillation results in a better product which has found some favour in India in linseed-oil varnishes giving a tack-free glossy finish. An oil obtained from the latex was formerly used in linoleum, oilskin, and leather cloth industries. Methane can be produced by anaerobic fermentation of the latex. The wood is white, close grained and fairly hard. It is rarely attacked by insects. It is used for toys, rafters and veneers. The wood is used for fuel when better options are unavailable, and it gives a charcoal suitable for gun-powder, and for the manufacture of fireworks. Dynamic accumulator.

Alcohol: Used for fuel etc. (this is wood alcohol, it is not the sort that can be drunk.

Biomass: Provides a large quantity of plant material that can be converted into fuel etc.

Charcoal: Used for fuel, drawing, deodorant, filter, fertilizer etc.

Fencing: Plants that can be used for fencing.

Fuel: Usually wood, plant materials that have been mentioned as being a good fuel.

Hedge: Plants that can be grown as hedges.

Insecticide: Kills insects.

Latex: A source of rubber.

Parasiticide: Kills external body parasites such as hair lice.

Resin: Used in perfumery, medicines, paints, soap making etc. This also includes turpentine, which is extracted from many resins and used as a preservative, water proofer etc,

Soil reclamation: Plants that can be grown in such circumstances an the spoil tips of mines in order to restore fertility.

Soil stabilization: Plants that can be grown in places such as sand dunes in order to prevent erosion by wind, water or other agents.

Agroforestry Services: Living fence: Simply managed rows of shrubs and trees.

Industrial Crop: Biomass: Three broad categories: bamboos, resprouting woody plants, and giant grasses. uses include: protein, materials (paper, building materials, fibers, biochar etc.), chemicals (biobased chemicals), energy - biofuels

Industrial Crop: Hydrocarbon: Materials, chemicals and energy include bioplastics, rubber, biomass products gasoline, jet fuel, diesel, butane, propane, biogas. Plants are usually resprouting plants and saps.

Management: Coppice: Cut to the ground repeatedly - resprouting vigorously. Non-destructive management systems maintaining the soil organic carbon.

Minor Global Crop: These crops are already grown or traded around the world, but on a smaller scale than the global perennial staple and industrial crops, The annual value of a minor global crop is under $1 billion US. Examples include shea, carob, Brazil nuts and fibers such as ramie and sisal.

Agroforestry Services: Living fence: Simply managed rows of shrubs and trees.

Management: Coppice: Cut to the ground repeatedly - resprouting vigorously. Non-destructive management systems maintaining the soil organic carbon.

Carbon Farming: Plants that can be a critical part of the solution to climate problems. The Carbon Farming Solution - Eric Toensmeier.

Coppice: A traditional method of woodland management which exploits the capacity of many species of trees to put out new shoots from their stump or roots if cut down.

Dynamic accumulator: Plants that gather minerals or nutrients from the soil and store them in a more bioavailable form and in high concentration in their tissues. Used as fertilizer or to improve mulch.

Hedge: Hedge

How it is grown

Succeeds in subtropical to tropical regions at elevations from sea level to 2,000 metres. The plant is very well adapted to semi-arid conditions, but also occurs in both dry and moist forest, savannah and shrub land, and also withstands salt stress associated with coastal conditions. It grows best in areas where annual daytime temperatures are within the range 25 - 37°c, but can tolerate 12 - 41°c. Plants are not tolerant of frost. It prefers a mean annual rainfall in the range 400 - 800mm, but tolerates 250 - 1,000mm. The plant can grow in areas where the mean annual rainfall can range from 250 - 4,000mm. Requires a sunny position. Appears to grow on almost any soil type. Prefers a wide variety of well-drained, light-textured, neutral to acidic soils. Prefers a pH in the range 5.5 - 6.5, tolerating 4.5 - 7.5. Established plants are very drought tolerant. Plants are very tolerant of trimming and also coppice well when cut at 20 - 30cm height. Under semi arid conditions regrowth is excellent. A density of 10,000 - 20,000 plants per hectare is normal when grown as a fuel crop. When planted at a spacing of 1metre x 1metre it produced 120 tonnes/ha fresh material and 14 tonnes/ha dry matter after 1 year, yielding 40 - 88 kg of crude oil, 135 - 213 kg of sugar and 1.8 tonnes of bagasse. There have been plantings of E. Tirucalli in Okinawa which on a spacing of 120cm between bushes are expected to yield 11 - 22 barrels of oil per hectare each year. Plants are not resistant to fire. Plants usually produce male flowers. Female flowers or plants are much less common. Plants with bisexual flowers also occur, although the female flower apparently often aborts. Flowering Time: Late Winter/Early Spring Late Summer/Early Fall. Blooming Color: "Pale Yellow Inconspicuous/none". Spacing: 6-8 ft. (1.8-2.4 m). Drought-tolerant; suitable for xeriscaping. Suitable for growing in containers.

Propagating it: Seed - Cuttings root easily. Cut fresh branches from a healthy bush. Cuttings should be at least 10cm long, and should be left to dry for at least 24 hours before planting. For ornamental purposes, cuttings of 35 - 40cm long are usually taken and for hedges cuttings of up to 1 metre long can be used. Take care to avoid direct contact with the milky sap, which can cause skin irritation. Plant at the onset of the rainy season in shallow trenches about 20 cm deep where water can collect.

Best place to grow:

Habit: Shrub

Hardiness: 9-12

Growth: Slow

Soil: Light (sandy), medium, heavy (clay)

Shade: Semi-shade, no shade

Moisture: Dry, moist

Things to keep in mind

The caustic, irritant sap contains a latex and is highly poisonous, causing severe injury to the eye, irritation and vesication from contact, emesis and purgation from ingestion. Eye contact with the sap can cause blindness lasting several days. The toxicity of the latex is considered seasonal or reduced in young plant parts, and young branches are even roasted and chewed. The extracts of the plant contain a number of esters of the tetracyclic diterpenoid phorbol, many of which have been shown to act as tumour promoters (cocarcinogens). Their co-carcinogenic effect on lymphoblastoid cells poses a real threat in Africa where drinking water is drawn around the plants. In East Africa the latex is commonly used as arrow poison and as an ingredient for bait to kill rodents and other wild animals; the pulped stems are thrown in water as fish poison. In south-western DR Congo the latex has been used in high doses as a trial by ordeal poison; in various countries it is used as criminal poison. (All parts of plant are poisonous if ingested Handling plant may cause skin irritation or allergic reaction )

Its other names

Local names

African Milkbush, Pencil Cactus, Milk Bush, Pencil Euphorbia, Rubber Hedge Euphorbia, Hejiyemukaka, Ingotsha, Ipupu, Kinchub, Lunsonga, Macussupu, Menjeve, Rusungwe, african milkbush, almeidinha, almeidinha (dried latex), aveloz, avelós, bois de lait, bois malgache, calli, cassoneira, consuelda, euforbia, euphorbe antivenerien, euphorbe effilée, famamo, famata, famata laro, finger euphorbia, finger tree, fingertree, gummieuforbia, indian tree spurge, laro, latex-wolfsmilch, liane calli, milk bush, milkbush, milkhedge, modu kalli, naked-lady, pencil tree, penciltree, petroleum plant, petroleum-plant, rubber euphorbia, rubber hedge euphorbia, tirucalli.

Synonyms

Arthrothamnus bergii Klotzsch & Garcke Arthrothamnus ecklonii Klotzsch & Garcke Arthrothamnus tiruca

African Milkbush, Pencil Cactus, Milk Bush Euphorbia tirucalli