''Euphorbia abyssinica'', commonly known as the desert candle or candelabra spurge, is a species of

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...

in the family

Euphorbiaceae Euphorbiaceae, the spurge family, is a large family of flowering plants. In English, they are also commonly called euphorbias, which is also the name of a genus in the family. Most spurges, such as ''Euphorbia paralias'', are herbs, but some, e ...

. ''E. abyssinica'' is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Ethiopia Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...

Somalia Somalia, , Osmanya script: 𐒈𐒝𐒑𐒛𐒐𐒘𐒕𐒖; ar, الصومال, aṣ-Ṣūmāl officially the Federal Republic of SomaliaThe ''Federal Republic of Somalia'' is the country's name per Article 1 of thProvisional Constituti ...

Sudan Sudan ( or ; ar, السودان, as-Sūdān, officially the Republic of the Sudan ( ar, جمهورية السودان, link=no, Jumhūriyyat as-Sūdān), is a country in Northeast Africa. It shares borders with the Central African Republic t ...

and

Eritrea Eritrea ( ; ti, ኤርትራ, Ertra, ; ar, إرتريا, ʾIritriyā), officially the State of Eritrea, is a country in the Horn of Africa region of Eastern Africa, with its capital and largest city at Asmara. It is bordered by Ethiopia ...

. It was first described in 1791, by the German botanist

Johann Friedrich Gmelin , fields = , workplaces = University of GöttingenUniversity of Tübingen , alma_mater = University of Tübingen , doctoral_advisor = Philipp Friedrich GmelinFerdinand Christoph Oetinger , academic_advisors = , doctora ...

. In its native habitat, it can grow up to tall. The woody stem is used for firewood and as timber in roofing, furniture and other items, and the sap is used in traditional medicine. It is also cultivated as an ornamental house plant.

Description

''E. abyssinica'' is a large, succulent, erect tree-like plant growing to a height of about . It can grow singly or form candelabra-like clumps. The main stem becomes woody as it ages, and sends out green side branches; these have between five and eight ribs or angles and branch at intervals. The terminal branches have three to five ribs, typically four. The ribs of new shoots bear small rounded protuberances, and it is on these that the leaves, flowers and fruit grow. The leaves are small, leathery and oval, and these soon fall in the dry season. The flowers have distinctive yellowish bracts but no petals; the male flowers have a single

stamen The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filame ...

, and the female flowers a stalked

pistil Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) ''pistils'' ...

and branched stigmas. The fruits are capsules with three compartments. The plants exude

toxic Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subst ...

latex-like sap which can cause blindness, and irritation and blistering of the skin.

Taxonomy

''Euphorbia abyssinica'' was first described as a species by

in 1791. Gmelin referred to an illustration in a book by

James Bruce James Bruce of Kinnaird (14 December 1730 – 27 April 1794) was a Scottish traveller and travel writer who confirmed the source of the Blue Nile. He spent more than a dozen years in North Africa and Ethiopia and in 1770 became the first Europ ...

first published in 1790.

Carl Ludwig Willdenow Carl Ludwig Willdenow (22 August 1765 – 10 July 1812) was a German botanist, pharmacist, and plant taxonomist. He is considered one of the founders of phytogeography, the study of the geographic distribution of plants. Willdenow was als ...

in his 1799 revision of

Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

's ''

Species Plantarum ' (Latin for "The Species of Plants") is a book by Carl Linnaeus, originally published in 1753, which lists every species of plant known at the time, classified into genera. It is the first work to consistently apply binomial names and was the ...

'' treated the plant in the same illustration as the variety β ''kolquall'' of ''Euphorbia officinarum''. The description by Bruce refers to the "eyes" on the sides having "five thorns", a feature Gmelin regarded as distinctive. However, as

N. E. Brown Nicholas Edward Brown (11 July 1849 in Redhill, Surrey – 25 November 1934 in Kew Gardens, London) was an English plant taxonomist and authority on succulents. He was also an authority on several families of plants, including Asclepiadacea ...

noted in 1912, the illustration shows paired thorns. In the same work, Brown described five other species of ''Euphorbia'' that he considered distinct from ''E. officinarum'', but which

Plants of the World Online Plants of the World Online (POWO) is an online database published by the Royal Botanic Gardens, Kew. It was launched in March 2017 with the ultimate aim being "to enable users to access information on all the world's known seed-bearing plants by ...

treated as synonyms of ''E. abyssinica'', : ''E. acrurensis'', ''E. controversa'', ''E. disclusa'', ''E. erythraeae'' (elevated from a variety) and ''E. neglecta''.

Phylogeny

molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

study in 2011 found that ''E. officinarum'' was a member of a well supported

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

within ''Euphorbia'' sect. ''Euphorbia''. Two of its closest relatives, ''

Euphorbia ingens ''Euphorbia ingens'' is a species of flowering plant in the family Euphorbiaceae. It is native to dry areas of southern Africa. It is popularly known as the candelabra tree or naboom. Its milky latex can be extremely poisonous and is a dangerous ...

'' and ''

Euphorbia ampliphylla ''Euphorbia ampliphylla'' is a succulent rainforest tree of the montane rainforests throughout East Africa and belonging to the Spurge Family (Euphorbiaceae). The branches are succulent and three-winged and pachycaulous. Like most euphorbs, i ...

'', are also from eastern Africa and form giant trees at maturity. The other two species in the clade also form a basal trunk or caudex, distinct from the branches.

Distribution and habitat

''E. abyssinica'' is native to the

Horn of Africa The Horn of Africa (HoA), also known as the Somali Peninsula, is a large peninsula and geopolitical region in East Africa.Robert Stock, ''Africa South of the Sahara, Second Edition: A Geographical Interpretation'', (The Guilford Press; 2004), ...

where it grows in

and

. It is found on arid hillsides, in montane woodland and on scrubby savannahs, sometimes in dense groves and other times growing by itself. It occurs at altitudes of .

Uses

''Euphorbia abyssinica'' is cultivated as an ornamental house plant, being promoted for its architectural form and ease of maintenance. It is also grown as a garden plant in suitable climates, including under its synonym ''Euphorbia acrurensis''. In its native countries, the woody tree-like stem is used for firewood and as timber in roofing, furniture, wooden saddles and other items. The sap can be used to kill ticks on cattle. In traditional medicine, the sap has been mixed with butter to treat fungal infections of the skin. The sap has also been used in cases of

visceral leishmaniasis Visceral leishmaniasis (VL), also known as kala-azar (Hindi: kālā āzār, "black sickness") or "black fever", is the most severe form of leishmaniasis and, without proper diagnosis and treatment, is associated with high fatality. Leishmaniasis ...

and

malaria Malaria is a mosquito-borne infectious disease that affects humans and other animals. Malaria causes symptoms that typically include fever, tiredness, vomiting, and headaches. In severe cases, it can cause jaundice, seizures, coma, or death. S ...

. It has also been found to promote the rooting of cuttings of such plants as ''

Boswellia papyrifera ''Boswellia papyrifera'', also known as the Sudanese frankincense, is a species of flowering plant and frankincense that is native to Ethiopia, Eritrea and Sudan. The tree is cultivated in Ethiopia because of its valuable resin. The incense is c ...

''. This is because the sap contains the growth regulator hormone

indole-3-acetic acid Indole-3-acetic acid (IAA, 3-IAA) is the most common naturally occurring plant hormone of the auxin class. It is the best known of the auxins, and has been the subject of extensive studies by plant physiologists. IAA is a derivative of indole, co ...

; branches and twigs that become detached root easily, and the plant is sometimes used to form a living fence. When propagated by cuttings, ''E. abyssinica'' does not develop the distinctive trunk different in appearance from the branches that is characteristic of naturally occurring plants.

References

{{Taxonbar, from=Q3734564 abyssinica Plants described in 1791 Taxa named by Johann Friedrich Gmelin Flora of Northeast Tropical Africa