Monadenium
       

      Monadenium  

      Euphorbia


      Euphorbia cf. serrata
      Scientific classification
            Kingdom:Plantae

            Division:Magnoliophyta

            Class:Magnoliopsida

            Subclass:Rosidae

            (unranked):Eurosids I

            Order:Malpighiales

            Family:Euphorbiaceae

            Subfamily:Euphorbioideae

            Tribe:Euphorbieae

            Subtribe:Euphorbiinae

            Genus:Euphorbia
            L.

      Diversity
      c.2160 species
      Type species
      Euphorbia serrata

      Subgenera
      Chamaesyce
      Esula
      Euphorbia
      Rhizanthium
      and see below
      Synonyms
      Chamaesyce
      Elaeophorbia
      Endadenium
      Monadenium
      Synadenium
      Pedilanthus

Euphorbia is a genus of plants belonging to the family Euphorbiaceae. Consisting 
of about 2160 species, Euphorbia is one of the most diverse genera in the plant 
kingdom. Members of the family and genus are sometimes referred to Spurges. The 
genus is primarily found in the tropical and subtropical regions of Africa and 
the Americas, but also in temperate zones worldwide. Succulent species originate 
mostly from Africa, the Americas and Madagascar. There exists a wide range of 
insular species, namely on the Hawaiian Islands where spurges are collectively 
known as ʻakokoverification needed
The common name "spurge" derives from the Middle English/Old French espurge ("to 
purge"), due to the use of the plant's sap as a purgative.
The botanical name Euphorbia derives from Euphorbus, the Greek physician of king 
Juba II of Numidia (52-50 BC - 23 AD). He is reported to have used a certain 
plant, possibly Resin Spurge (E. resinifera), as a herbal remedy when the king 
suffered from a swollen bellyverification needed. Carolus Linnaeus assigned the 
name Euphorbia to the entire genus in the physician's honor.[1]
Juba II himself was a noted patron of the arts and sciences and sponsored 
several expeditions and biological research. He also was a notable author, 
writing several scholarly and popular scientific works such as treatises on 
natural history or a best-selling traveller's guide to Arabia. Euphorbia 
regisjubae (King Juba's Euphorbia) was named to honor the king's contributions 
to natural history and his role in bringing the genus to notice.
      Contents
        1 Description 
          1.1 Xerophytes and succulents 
          1.2 Toxicity 
        2 Uses 
        3 Systematics and taxonomy 
          3.1 Selected species 
          3.2 Subgenera 
        4 Footnotes 
        5 References 
        6 External links 


Description
The plants are annual or perennial herbs, woody shrubs or trees with a caustic, 
poisonous milky sap (latex). The roots are fine or thick and fleshy or tuberous. 
Many species are more or less succulent, thorny or unarmed. The main stem and 
mostly also the side arms of the succulent species are thick and fleshy, 15-91 
cm (6-36 inches) tall. The deciduous leaves are opposite, alternate or in 
whorls. In succulent species the leaves are mostly small and short-lived. The 
stipules are mostly small, partly transformed into spines or glands, or missing.
Like all members of the family Euphorbiaceae, all spurges have unisexual 
flowers. In Euphorbia these are greatly reduced and grouped into pseudanthia 
called cyathia. The majority of species are monoecious (bearing male and female 
flowers on the same plant), although some are dioecious with male and female 
flowers occurring on different plants. It is not unusual for the central cyathia 
of a cyme to be purely male, and for lateral cyathia to carry both sexes. 
Sometimes young plants or those growing under unfavourable conditions are male 
only, and only produce female flowers in the cyathia with maturity or as growing 
conditions improve. The bracts are often leaf-like, sometimes brightly coloured 
and attractive, sometimes reduced to tiny scales. The fruits are three (rarely 
two) compartment capsules, sometimes fleshy but almost always ripening to a 
woody container that then splits open (explosively). The seeds are 4-angled, 
oval or spherical, and in some species have a caruncle.
Xerophytes and succulents
In the genus Euphorbia succulence in the species has often evolved divergently 
and to differing degrees. Sometimes it is difficult to decide, and it is a 
question of interpretation, whether or not a species is really succulent or 
"only" xerophytic. In some cases, especially with geophytes, plants closely 
related to the succulents are normal herbs. About 850 species are succulent in 
the strictest sense. If one includes slightly succulent and xerophytic species, 
this figure rises to about 1000, representing about 45% of all Euphorbia 
species.
Toxicity
The latex (milky sap) of spurges acts as a deterrent for herbivores as well as a 
wound healer. Usually it is white, but in rare cases (e.g. E. abdelkuri) yellow. 
As it is under pressure, it runs out from the slightest wound and congeals 
within a few minutes of contact with the air. Among the component parts are many 
di- or tri-terpen esters, which can vary in composition according to species, 
and in some cases the variant may be typical of that species. The terpen ester 
composition determines how caustic and irritating to the skin it is. In contact 
with mucous membranes (eyes, nose, mouth) the latex can produce extremely 
painful inflammation. In experiments with animals it was found that the terpen 
ester resiniferatoxin had an irritating effect 10,000 to 100,000 times stronger 
than capsaicin, the "hot" substance found in chillies. Several terpen esters are 
also known to be carcinogenic.
Therefore spurges should be handled with caution. Latex coming in contact with 
the skin should be washed off immediately and thoroughly. Partially or 
completely congealed latex is often no longer soluble in water, but can be 
removed with an emulsion (milk, hand-cream). A physician should be consulted 
regarding any inflammation of a mucous membrane. It has been noticed, when 
cutting large succulent spurges in a greenhouse, that vapours from the latex 
spread and can cause severe irritation to the eyes and air passages several 
metres away. Precautions, including sufficient ventilation, are required. Small 
children and domestic pets should be kept from contact with spurges.
Uses
Several spurges are grown as garden plants, among them Poinsettia (E. 
pulcherrima) and the succulent E. trigona. E. pekinensis (Chinese: 大戟; pinyin: 
dàjǐ) is used in traditional Chinese medicine, where it is regarded as one of 
the 50 fundamental herbs. Several Euphorbia species are used as food plants by 
the larvae of some Lepidoptera (butterflies and moths), including the Giant 
Leopard Moth.
Systematics and taxonomy
According to recent studies of DNA sequence data[2] most of the smaller 
"satellite genera" around the huge genus Euphorbia nest deep within the latter. 
Consequently these taxa, namely the never generally accepted genus Chamaesyce as 
well as the smaller genera Cubanthus,[3] Elaeophorbia, Endadenium, Monadenium, 
Synadenium and Pedilanthus were transferred to Euphorbia. The entire subtribe 
Euphorbiinae now consists solely of the genus Euphorbia.
Selected species
See List of Euphorbia species for complete list.
  Euphorbia albomarginata – Rattlesnake Weed, White-margined Sandmat 
  Euphorbia amygdaloides – Wood Spurge 
  Euphorbia antisyphilitica – Candelilla 
  Euphorbia bulbispina 
  Euphorbia cyparissias – Cypress Spurge 
  Euphorbia decidua 
  Euphorbia elastica – (Mexican) Palo Amarillo 
  Euphorbia esula – Leafy Spurge 
  Euphorbia franckiana 
  Euphorbia helioscopia – Sun Spurge 
  Euphorbia heterophylla – Painted Euphorbia, Desert Poinsettia, (Mexican) 
  Fireplant, Paint Leaf, Kaliko 
  Euphorbia labatii 
  Euphorbia lactea – Mottled Spurge, Frilled Fan, Elkhorn 
  Euphorbia lathyris – Caper Spurge, Paper Spurge, Gopher Spurge, Gopher Plant, 
  Mole Plant 
  Euphorbia maculata – Spotted Spurge, Prostrate Spurge 
  Euphorbia maritae 
  Euphorbia milii – Crown-of-thorns, Christ Plant 
  Euphorbia myrsinites – Myrtle Spurge, Creeping Spurge, donkey tail 
  Euphorbia peplis – Purple Spurge 
  Euphorbia peplus – Petty Spurge 
  Euphorbia pulcherrima – Poinsettia, Mexican Flame Leaf, Christmas Star, Winter 
  Rose, Noche Buena, Lalupatae, Pascua, Atatürk çiçeği (Turkish) 
  Euphorbia resinifera – Resin Spurge 
  Euphorbia serrata – Serrated spurge, Sawtooth spurge 
  Euphorbia tirucalli – Indian Tree Spurge, Milk Bush, Pencil Tree 
  Euphorbia tithymaloides – Devil's Backbone, "Redbird cactus", cimora misha 
  (Peru) 
  Euphorbia virosa 
Subgenera
 

Simplified diagram of relations in subtribe Euphorbiinae
The genus Euphorbia is one of the largest and most complex genera of flowering 
plants and several botanists have made unsuccessful attempts to subdivide the 
genus into numerous smaller genera. According to the recent phylogenetic 
studies,[2] Euphorbia can be divided into 4 subgenera, each containing several 
not yet sufficiently studied sections and groups. Of these, Esula is the most 
basal. Chamaesyce and Euphorbia are probably sister taxa but very closely 
related to Rhizanthium. Extensive xeromorph adaptations in all probability 
evolved several times; it is not known if the common ancestor of the cactus-like 
Rhizanthium and Euphorbia lineages was xeromorphic - in which case a more normal 
morphology would have re-evolved namely in Chamaesyce - or whether extensive 
xeromorphism is entirely polyphyletic even to the level of the subgenera.
  Esula 

      Wood Spurge
      Euphorbia amygdaloides
      Cypress Spurge
      Euphorbia cyparissias
      Leafy Spurge
      Euphorbia esula
      Myrtle Spurge
      Euphorbia myrsinites

  Rhizanthium 

      Euphorbia ferox
      Euphorbia flanaganii
      Euphorbia meloformis ssp. valida
      Euphorbia obesa ssp. symmetrica

  Chamaesyce 

      Euphorbia celastroides
      Painted Euphorbia
      Euphorbia heterophylla
      Poinsettia
      Euphorbia pulcherrima
      Euphorbia rivae

  Euphorbia 

      Euphorbia actinoclada
      Euphorbia attastoma var. attastoma
      Euphorbia confinalis ssp. rhodesica
      Euphorbia lupulina

Footnotes
  ^ Linnaeus (1753): p.450 
  ^ a b Steinmann & Porter (2002), Steinmann (2003), Bruyns et al. (2006) 
  ^ Steinmann, van Ee, Berry & Gutiérrez (2007) in Anales del Jardín Botánico de 
  Madrid 
References
  Bruyns, Peter V. & al. (2006): A new subgeneric classification for Euphorbia 
  (Euphorbiaceae) in southern Africa based on ITS and psbA-trnH sequence data. 
  Taxon 55(2): 397–420. HTML abstract 
  Buddensiek, Volker (2005): Succulent Euphorbia plus (CD-ROM). Volker 
  Buddensiek Verlag. 
  Carter, Susan (1982): New Succulent Spiny Euphorbias from East Africa 
  Carter, Susan & Eggli, Urs (1997): The CITES Checklist of Succulent Euphorbia 
  Taxa (Euphorbiaceae) 
  Carter, Susan & Smith, A.L. (1988): Flora of Tropical East Africa, 
  Euphorbiaceae 
  Linnaeus, Carolus (1753): Species Plantarum (1st ed.) 
  Noltee, Frans (2001): Succulents in the wild and in cultivation, Part 2 
  Euphorbia to Juttadinteria (CD-ROM) 
  Eggli, Urs (ed.) (2002): Sukkulentenlexikon (Vol. 2: Zweikeimblättrige 
  Pflanzen (Dicotyledonen)). Eugen Ulmer Verlag. 
  Everitt, J.H.; Lonard, R.L., Little, C.R. (2007). Weeds in South Texas and 
  Northern Mexico. Lubbock: Texas Tech University Press.  ISBN 0-89672-614-2 
  Pritchard, Albert (2003): Introduction to the Euphorbiaceae 
  Schwartz, Herman (ed.) (1983): The Euphorbia Journal Strawberry Press, Mill 
  Valley, California, USA 
  Singh, Meena (1994): Succulent Euphorbiaceae of India. Mrs. Meena Singh, A-162 
  Sector 40, NOIDA, New Delhi, India. 
  Steinmann, V.W. (2003): The submersion of Pedilanthus into Euphorbia 
  (Euphorbiaceae). Acta Botanica Mexicana 65: 45-50. PDF fulltext [English with 
  Spanish abstract] 
  Steinmann, V.W. & Porter, J.M. (2002): Phylogenetic relationships in 
  Euphorbieae (Euphorbiaceae) based on ITS and ndhF sequence data. Annals of the 
  Missouri Botanical Garden 89(4): 453–490. doi:10.2307/3298591 (HTML abstract, 
  first page image) 
  Turner, Roger (1995): Euphorbias - A Gardeners' Guide. Batsford, England. 
External links
Wikimedia Commons has media related to: 
Euphorbia
  / Euphorbia 
  International Euphorbia Society 
  Succulent Euphorbias 
  A selection of important / new literature 
  U4BA - Euphorbia for you 
  Euphorbia and the other succulents 
  The Euphorbia Family 
  ITIS 
  IPNI 
  Flora Zambesiaca: Euphorbia 


