If you have purchased a tall, columnar, cactus-like succulent labelled « Euphorbia eritrea » or « Euphorbia erythraea » at a garden centre, a home furnishing store, or from an online plant shop, you own a plant whose label bears a name that does not exist in botanical nomenclature. The species you almost certainly possess is Euphorbia abyssinica J.F.Gmel. — the desert candle of the Horn of Africa. This article explains the nomenclatural fiction behind the trade name, introduces the real Euphorbia abyssinica, and helps you distinguish it from the two species with which it is most frequently confused: Euphorbia ingens and Euphorbia ammak. It belongs to the genus Euphorbia within the family Euphorbiaceae.
Why « Euphorbia eritrea » Doesn’t Exist
The name « Euphorbia eritrea » (or « Euphorbia erythraea ») is one of the most widespread phantom names in the houseplant industry. It appears on plant labels in IKEA, Jardiland, Truffaut, and countless online retailers. Yet it has no standing whatsoever in botanical nomenclature. Here is the trail of the confusion:
- The original variety: In 1906, the German botanist Alwin Berger described a variety of the Ethiopian species Euphorbia abyssinica from Eritrea and named it Euphorbia abyssinica var. erythraeae A.Berger. This is a validly published varietal name — it designates a geographical form of Euphorbia abyssinica from the Eritrean portion of the species’ range.
- An illegitimate elevation: In 1912, N.E. Brown attempted to elevate Berger’s variety to species rank as Euphorbia erythraeae (Berger) N.E.Br. However, this name was illegitimate (nom. illeg.) because a completely unrelated species — Euphorbia erythraea Hemsl., a small herbaceous euphorbia from East Asia (now a synonym of Euphorbia sieboldiana) — already existed. Two different species cannot share the same name.
- The commercial shortcut: The horticultural trade, either unaware of or indifferent to these nomenclatural rules, adopted the geographically evocative name « Euphorbia eritrea » as a selling label for large columnar euphorbias of the abyssinica complex sourced from nursery production. The result: millions of plants worldwide bear a name that is botanically meaningless.
- What POWO says: Plants of the World Online (Royal Botanic Gardens, Kew) lists Euphorbia abyssinica var. erythraeae and Euphorbia erythraeae (Berger) N.E.Br. as synonyms of Euphorbia abyssinica J.F.Gmel. There is no accepted species called Euphorbia eritrea or Euphorbia erythraea in the succulent euphorbia group.
Bottom line: if your plant label says « Euphorbia eritrea », read Euphorbia abyssinica.
Taxonomy and Nomenclature
Accepted name: Euphorbia abyssinica J.F.Gmel., Systema Naturae, ed. 13bis, 2(1): 759 (1791).
Euphorbia abyssinica was described by Johann Friedrich Gmelin in 1791, based on an illustration in James Bruce’s Travels to Discover the Source of the Nile (1790). The specific epithet abyssinica refers to Abyssinia, the historical name for the Ethiopian Empire.
Synonyms (POWO — 13 recorded): The most frequently encountered in the trade and literature include:
- Euphorbia abyssinica var. erythraeae A.Berger (1906) — the source of the trade name « Euphorbia eritrea »
- Euphorbia erythraeae (Berger) N.E.Br. (1912) — nom. illeg. (illegitimate later homonym)
- Euphorbia acrurensis N.E.Br. (1912) — another synonym commonly used in the trade, particularly for plants from the Eritrean highlands
- Euphorbia grandis Lem. (1857)
- Euphorbia obovalifolia A.Rich.
- Euphorbia officinarum var. kolquall Willd. (1799)
Common names: desert candle, candelabra spurge, Abyssinian euphorbia (English); qwolqwal (Amharic, Ethiopia); adaamii (Oromo, Ethiopia).
Classification: Family Euphorbiaceae, genus Euphorbia, subgenus Euphorbia.
Description
Euphorbia abyssinica is a large, spiny, succulent tree that can reach 9 to 10 m in height in its native habitat. It grows singly or forms multi-stemmed, candelabra-like clumps.
Trunk and Branches
The main stem becomes woody and stout with age, supporting a crown of erect green branches. The branches are conspicuously segmented, with five to eight ribs (angles) on the main limbs and typically three to five ribs (most commonly four) on the terminal branchlets. Each segment is 7 to 12 cm in diameter. The colour is a distinctive dark olive green — noticeably darker than the blue-green or grey-green of Euphorbia ammak or Euphorbia ingens.
Spines
Paired, short, stiff, needle-like spines line the edges of the ribs. The spines of Euphorbia abyssinica are generally more prominent, more closely spaced, and sharper than those of Euphorbia ammak — a useful, if subtle, diagnostic feature.
Leaves
Small, flat, tear-shaped leaves (up to approximately 5 cm long) appear at the tops and sides of the columns during the growing season, particularly in early summer and in shady conditions. They are rapidly deciduous.
Juvenile vs. Mature Form
A distinctive feature noted by experienced growers on the specialist forum Agaveville: Euphorbia abyssinica undergoes a striking morphological shift as it matures. Young plants produce the typical clean, upright, columnar branches familiar from the houseplant trade. Very large, old plants develop a dramatically different mature growth form: compact, thick, multi-ribbed growth (sometimes exceeding seven ribs) with a dense, almost monstrose appearance. Cuttings taken from this mature form look so different from juvenile material that they are frequently misidentified as a separate species — contributing to the chronic confusion surrounding this taxon in commerce.
Latex
Copious, milky-white, caustic, and toxic — as with all large succulent euphorbias. However, the latex of Euphorbia abyssinica contains a noteworthy phytochemical: indole-3-acetic acid (IAA), a natural auxin (plant growth hormone). This explains why branches and twigs that break off root with remarkable ease, and why the species is sometimes used in Africa as a natural rooting agent — branches of Euphorbia abyssinica placed alongside cuttings of other species (such as Boswellia papyrifera) have been shown to promote their root formation.
Distribution and Habitat
According to POWO, Euphorbia abyssinica is native to Djibouti, Eritrea, Ethiopia, Somalia, and Sudan–South Sudan. An introduced population is also recorded from the Balearic Islands (Spain).
In its native range, the species grows on steep, rocky hillsides in dry, semi-arid to sub-humid tropical climates, at elevations from 840 to 2,400 m. It sometimes forms pure stands and is locally abundant. A culturally notable feature in Ethiopia: Euphorbia abyssinica is frequently found growing around churches — likely a combination of deliberate planting (as living fences to protect sacred precincts) and passive protection from harvesting on consecrated ground.
Distinguishing Euphorbia abyssinica from Euphorbia ammak and Euphorbia ingens
The horticultural trade routinely confuses three large, columnar, candelabra-forming euphorbias. Here is how to tell them apart:
| Feature | Euphorbia abyssinica | Euphorbia ammak | Euphorbia ingens |
|---|---|---|---|
| Origin | Horn of Africa (Ethiopia, Eritrea, Somalia, Sudan) | Arabian Peninsula (Yemen, Saudi Arabia) | Southern & eastern Africa (Eritrea to South Africa) |
| Stem colour | Dark olive green | Blue-green to grey-green | Dark green to grey-green |
| Ribs on main branches | 5–8 (terminal: 3–5, usually 4) | 4 (rarely 5) | 4–5 |
| Spines | Short, sharp, closely spaced, prominent | Short, less prominent, more widely spaced | Very short (often < 5 mm), may be absent on old trees |
| Spine shields | Variable | Variable | Separate, not forming a continuous ridge |
| Mature form | Dramatically different from juvenile (compact, multi-ribbed, almost monstrose) | Relatively consistent throughout life | Consistent; lower branches persist |
| Variegated cultivar? | Yes (Euphorbia abyssinica var. erythraeae ‘Variegata’) — frequently mislabelled « Euphorbia eritrea Variegata » | Yes (Euphorbia ammak ‘Variegata’) — frequently mislabelled « Euphorbia ingens Variegata » | Rare in cultivation |
A practical note from specialist growers: The distinction between Euphorbia abyssinica and Euphorbia ammak is notoriously difficult from photographs alone. As one expert contributor on Agaveville observed: “once you’ve seen the real thing and grown the real thing, the differences are more easily noted” — but from images, misidentification is rampant. The safest approach for a grower receiving an unverified plant is to assess rib count, spine density, and stem colour in person, with awareness that young plants of both species can appear very similar.
Ethnobotanical Uses
Living Fence and Timber
Euphorbia abyssinica is widely used across the Horn of Africa as a living fence. Branches root readily (thanks to the IAA content of the latex) and rapidly form an impenetrable, toxic barrier. The woody trunk and main branches provide firewood and timber used for roofing, furniture, wooden saddles, and other items.
Traditional Medicine
The caustic latex has been used medicinally — mixed with butter to treat fungal skin infections, and applied in cases of visceral leishmaniasis and malaria. These uses carry significant risks due to the latex’s toxicity and should not be replicated without medical supervision.
Veterinary Use
The sap is used to kill ticks on cattle — a direct application of its irritant properties.
Cultivation
Euphorbia abyssinica is widely cultivated as a houseplant and, in suitable climates, as a garden specimen. It is valued for its bold architectural form, ease of maintenance, and tolerance of neglect.
Light
Full sun to bright indirect light. The species adapts well to indoor conditions provided it receives at least 5–6 hours of bright light daily. In full sun, growth is compact and the spines are well developed; in lower light, the plant etiolates.
Soil
Well-drained, mineral-rich substrate. A standard cactus and succulent mix is adequate. In the ground, tolerant of a range of soil types provided drainage is excellent.
Watering
Drought-tolerant. Water when the top several centimetres of soil are dry during the growing season; reduce dramatically in winter. Overwatering causes root rot.
Temperature and Hardiness
Euphorbia abyssinica is a tropical highland species with moderate frost tolerance — better than Euphorbia tirucalli but less than Euphorbia resinifera or Euphorbia antisyphilitica.
Experienced growers on DavesGarden report « excellent cold hardiness, at least down to 26 °F » (-3 °C). On Agaveville, a Californian grower in Tarzana reported that their Euphorbia abyssinica survived repeated overnight frosts to -2 °C (28 °F) over multiple years without any damage — even in exposed positions with no overhead canopy. The green (non-variegated) form appears more cold-tolerant than the variegated cultivar, which suffered minor rib damage during the same events.
Recommended USDA zones: 9b to 11 for permanent outdoor planting. In zone 9b, expect occasional cosmetic frost damage to rib edges during exceptional cold events, but the plant should survive. The variegated form is more frost-sensitive and is best treated as zone 10a minimum. For European growers, this remains primarily an indoor or greenhouse plant, to be moved outdoors only during the warm season.
Propagation
Remarkably easy by stem cuttings — aided by the natural IAA content of the latex. Cut a branch, wash the latex with water, allow to callus for 5–10 days, and plant in well-drained mix. Rooting is generally faster than with most other large columnar euphorbias.
Pests and Diseases
Minimal. Root rot from overwatering is the principal risk. Mealybugs and scale insects may occur on indoor specimens.
Toxicity and Safety
The latex is extremely caustic — identical precautions to those for Euphorbia ingens and Euphorbia tirucalli apply. Sealed goggles, thick gloves, no power tools, and immediate medical attention for eye contact. See our detailed safety sections in the Euphorbia ingens and Euphorbia tirucalli articles.
Conservation Status
Euphorbia abyssinica is not currently assessed as threatened by the IUCN. It is locally abundant in its native range, particularly in Ethiopia. Like all succulent Euphorbia species, it is listed on CITES Appendix II.
FAQ
My plant is labelled « Euphorbia eritrea ». Is that a real name?
No. The name « Euphorbia eritrea » (or « Euphorbia erythraea ») does not exist as a validly published species name for any succulent euphorbia. Your plant is almost certainly Euphorbia abyssinica, or possibly Euphorbia ammak. See the identification table above.
How do I tell if my plant is Euphorbia abyssinica or Euphorbia ammak?
Count the ribs: Euphorbia abyssinica typically has 4 ribs on terminal branches but 5–8 on older branches; Euphorbia ammak is consistently 4-ribbed. Check the colour: Euphorbia abyssinica is darker olive green; Euphorbia ammak is paler blue-green. Examine the spines: those of Euphorbia abyssinica are more prominent and closely spaced. In practice, young plants of both species are very difficult to distinguish.
Is the variegated plant sold as « Euphorbia eritrea Variegata » really Euphorbia abyssinica?
This is disputed. Many — perhaps most — variegated columnar euphorbias in the trade labelled « Euphorbia eritrea Variegata » or « Euphorbia ingens Variegata » are actually Euphorbia ammak ‘Variegata’. The true Euphorbia abyssinica var. erythraeae ‘Variegata’ exists but is less common. Without verified provenance, identification of variegated specimens is particularly unreliable.
Can Euphorbia abyssinica survive outdoors in Europe?
In the mildest Mediterranean coastal microclimates (USDA zone 9b–10a), the green form can survive outdoors with occasional cosmetic frost damage. Elsewhere, treat it as a houseplant or greenhouse specimen.
Sources and References
- Plants of the World Online (POWO), Royal Botanic Gardens, Kew — Euphorbia abyssinica J.F.Gmel. Accepted name.
- Wikipedia — Euphorbia abyssinica.
- Gmelin, J.F. (1791). Systema Naturae, ed. 13bis, 2(1): 759.
- Berger, A. (1906). Sukkulente Euphorbien: 73. — Original description of var. erythraeae.
- Brown, N.E. (1912). In Oliver et al., Flora of Tropical Africa, 6(1): 595–596. — Descriptions of E. acrurensis, E. controversa, E. disclusa, E. erythraeae, E. neglecta.
- Agaveville forum — Euphorbia abyssinica discussion thread. Detailed grower observations on identification, cold hardiness, and distinction from E. ammak.
- Useful Tropical Plants — Euphorbia abyssinica.
- Firsthand horticultural observations, Jardin Zoologique Tropical de La Londe-les-Maures, Var, France (USDA zone 9b).
Authority Pages — Best Online Resources
- POWO — Euphorbia abyssinica — Accepted name, 13 synonyms, distribution. The definitive taxonomic reference.
- World Flora Online — Euphorbia abyssinica — Morphological key characters.
- Wikipedia — Euphorbia abyssinica — Good general overview including ethnobotanical uses and IAA content.
- Useful Tropical Plants — Euphorbia abyssinica — Habitat, uses, and synonymy.
- FloraFinder — Euphorbia abyssinica — Photos and complete synonym list including illegitimate E. erythraeae.
- GBIF — Euphorbia abyssinica — Occurrence records and distribution map.
- Agaveville — Euphorbia abyssinica thread — The most detailed English-language discussion of identification, cold hardiness, and distinction from E. ammak, with photographs from multiple growers.
- iNaturalist — Euphorbia abyssinica — Georeferenced observations with photos from the wild and cultivation.