Origin and Habitat: Euphorbia beharensisSN|31684]]SN|31684]] is endemic to Taolanaro and Androy areas, Fort-dauphin area (Behara), Tulear area (Tsimanampetsotsa) in Southern and South-western Madagascar (extent of occurrence 24,253.2 km², area of occupancy 9,251.28 km²). Recorded from 14 localities and comprises four subpopulations (hence probably much fewer than ten locations). The population is highly fragmented.
Habitat and Ecology: Dry bush and open Didiereaceae forest, on sand on gneiss rocks. Threats to this taxon include habitat degradation, fire, habitat clearing for charcoal and collection for horticulture.

• Euphorbia beharensis Leandri

• Euphorbia beharensis var. guillemetii (Ursch & Leandri) Rauh
• Euphorbia guillemetii Ursch & Leandri

Description: Euphorbia beharensis is a much-branched shrubs with tuberous roots similar to Euphorbia milli but branches very slender, 3-5 mm thick, spines 1-1.5 cm long. The small green inflorescence are borne on short peduncle from branch apices.
Derivation of specific name: It is named after the location Behara in southern Madagascar.
Stems: Branches slender, about 5 mm in diameter up to 40 cm long.
Caudex. The caudex can grow to six centimetres.
Leaves: At branches tips, ovate, to 8 mm long and 4 mm wide, green, margin more or less undulate, subsessile, deciduous.
Stipular spines: Up to 1.5 cm long, base inflated, to 1 cm apart.
Inflorescences (cymes): Subterminal, 2- to 3-forked on peduncles about 1 cm long. Cyathophylls spreading.
Flowers (cyathia): 2 mm in diameter. Nectar-glands 2-lipped; Ovary ovoid.

Bibliography: Major references and further lectures
1) Werner Rauh, Herman Schwartz “Succulent and xerophytic plants of Madagascar” Volume 2 Strawberry Press, 1998
2) Urs Eggli “Illustrated Handbook of Succulent Plants: Dicotyledons” Volume 2. Springer, 2002
3) Haevermans, T. 2004. Euphorbia beharensis var. beharensis. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 09 August 2015.
4) The Euphorbia Journal 1: 58 (1983)
5) James Cullen, Sabina G. Knees, H. Suzanne Cubey “The European Garden Flora Flowering Plants: A Manual for the Identification of Plants Cultivated in Europe, Both Out-of-Doors and Under Glass” Cambridge University Press, 11/Aug/2011
6) Buddensiek, V. “Sukkulente Euphorbien” 1998.
7) Leandri, J. 1946. “Contribution a l'etude des Euphorbiacees de Madagascar, X. Euphorbes du groupe Diacanthium.” Notul. Syst. (Paris) 12: 156–170.
8) Rauh, W. 1999. "Weitere neue und wenig bekannte Euphorbien aus Madagaskar." Trop. Subtrop. Pflanzenwelt 100: 1–35.

Cultivation and Propagation: Euphorbia beharensis is only likely to be found in specialist collections. Cultivation of this plant is the same as that for the other shrubby varieties of Euphorbia from tropical areas (Madagascar, and central Africa), but it is one the easiest.
Growth rate: It is a relatively fast growing species.
Exposure: Full sun to lit shade appears to be the optimum range, but can tolerate the most shade, and a plant that has been growing in shade should be slowly hardened off before placing it in full sun as the plant will be severely scorched if moved too suddenly from shade into sun.
Waterings: Relatively flexible in its watering requirements. They can be watered regularly as long as the medium is open and well drained. As with any normal plant when watering, it is best to do so thoroughly, until a little water comes out through the drain holes. Allow the medium to dry out somewhat between waterings. Reduce watering to once every 1 month during winter. Space plants apart to allow air movement between branches and leaves. This will help with evaporation of extra water droplets collected during watering.
Soil: The ideal potting-medium is one with good moisture-retaining capacity but open and well drained with some extra manure for added nutrition.
Fertilization: Regular fertilizing with low nitrogen and high phosphorus and potassium ratios are preferred. Feed during spring and summer to mid autumn and withhold feeding during winter.
Maintenance: Tall plant will benefit from being staked, with bamboo or other suitable stakes. In the absence of staking, the stems of the plants may snap under the weight.
Hardiness: Very tender, protect from frost. As the natural way they need in winter at least 12 to 15 °, with adequate irrigation but have no problems with it, to stand next to radiators.
Pest and diseases: Mildew can occur in high humidity.
Propagation: Cuttings It is recommend taking Euphorbia cuttings in Spring/Summer when the plant is growing so that they have a better chance of success. They key is heat & good air circulation. These cuttings should be dipped in Hormone powder (but it is not needed) and left for a period of 3-4 weeks to callous. Then pot the cutting and don't water ( or kept slightly moist) until rooted. These will root just fine, if you can put the pot outside in the summer, or put pot on a heating pad.
Warning: The milky sap produced by this shrub has been known to cause burning and blistering of the skin, and even temporary blindness, and death may result if any of its parts are eaten. All of these problems can be avoided if care is taken when handling the plant.