Origin and Habitat: China (W Guangxi, S Sichuan, Taiwan, Yunnan), Bhutan, N and NE India, Myanmar, Nepal, Pakistan. In India Euphorbia royleanaSN|32938]]SN|32938]] is common on the dry and hot rocky slopes of the outer range; of the western Himalaya: from the Indus to Kamaon acending to an altitude of 2000 metres above sea level. It occur on the salt range in the Punjab. It is also commonly grown in the form of hedge in the sub-Himalayan tract end the adjacent plains. On the outer dry slopes of western Nepal usually it is found between an elevation of 1,000 to 1,500 metres.
Habitat and ecology: Euphorbia royleanaSN|32938]]SN|32938]] is a relatively rare fleshy shrub, mainly found in subtropical rain-shadow valleys and hot rocky slopes. It grows on a variety of soils comprising sandy, lateritic or salty soils. It can be noticed from distance for its cactus like appearance on dry or rocky hill slopes.

• Euphorbia royleana Boiss.
• Euphorbia pentagona Royle

Description: Euphorbia royleanaSN|32938]]SN|32938]] is a deciduous, cactus-like, shrub or small upright trees up to 2-5(-7) m high, armed with short prickles, with a stout trunk and; glabrous except for cyathia. The stems become leafless during hot and cold seasons. The flowers (cyathia) are small greenish-yellow, 3-4 in almost stalkless clusters in leaf axils
Stems: It has succulent segmented branches in whorls, green, 4-7(-8) cm thick, many branching from upper parts.
Ribs: 5(-7), angles more or less undulately winged with rounded teeth/tubercles.
Roots: Has stout tap roots.
Leaves: Alternate, apically clustered, produced in moist season soon falling, usually not seen when in flower. Leaf blade fleshy oblanceolate, spathulate, or spoon-shaped 5-15 long, 1-4 cm wide, slightly succulent, base attenuate, margin entire, apex obtuse or subtruncate. Veins inconspicuous. Petiole absent.
Stipular spines: Small in pairs on the edges on distinct shield, with broad flat faces between, 3-5 mm long.
Cyathia: Greenish-yellow, almost stalkless, 3-4 in subterminal cymes in leaf axils. Peduncle about 5 mm long. Cyathophylls as long as involucre, membranous. Involucre ca. 2.5 × 2.5 mm. Nectar-glands 5, transversely elliptic, dark yellow.
Capsules: Trigonous, 1-1.2 × 1-1.5 cm, light reddish brown, smooth and glabrous.
Phenology: Flowering & Fruiting in spring to early summer (March-July). Seeding time June-October.
Seeds: 3-3.5 × 2.5-3 mm, brown, adaxially striate; caruncle absent.

Bibliography: Major references and further lectures
1) D. Jesse Wagstaff “International Poisonous Plants Checklist: An Evidence-Based Reference” CRC Press, 07 July 2008
2) Spoerke, Susan C. Smolinske “Toxicity of Houseplants” CRC Press, 03 July 1990
3) Chopra R N “Indigenous Drugs Of India” Academic Publishers, 1933
4) Werner Rauh “The Wonderful World of Succulents: Cultivation and Description of Selected Succulent Plants Other Than Cacti” Smithsonian Institution Press, 1984
5) Urs Eggli “Illustrated Handbook of Succulent Plants: Dicotyledons” Springer Science & Business Media, 2002
6) V. Singh, R. P. Pandey “Ethnobotany of Rajasthan, India” Scientific Publishers, 01 january 1998
7) “Euphorbia pentagona” in Flora of China @ efloras.org <http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=242321511> FOC Vol. 11 Page 289, 300 accessed on 1 May 2016.
8) Ajit Kumar Banerjee “Shrubs in Tropical Forest Ecosystems: Examples from India.” World Bank Technical Paper (WTP- 103), July 1989, Public Disclosure Authorized, retrieves 01 May 2016 from <http://www-wds.worldbank.org/servlet/WDSContentServer/IW3P/IB/1999/11/19/000178830_9810190413474/Rendered/PDF/multi_page.pdf>

Cultivation and Propagation: Euphorbia royleanaSN|32938]]SN|32938]] is a columnar Euphorbia, known in it native country for being a bit of a weed, and a toxic one, too. It is a easy to grow plant for pot culture. It is a nice ornamental with columnar stems and minimal if any spines. It grows well in a very draining mineral potting substrate, but it isn't picky about soil. Out doors it requires a deep sandy soil, but tends to leaf out in warm, wet times. Can be used in the ground (in areas of mild winters) as an accent or landscape specimen, for its form. It can easily be grown in a patio container.
Growth rate: Growth rate is moderate and it adapts itself well to container culture.
Sun tolerance: It can tolerate full sun but may look better in light afternoon shade.
Watering and feeding: It needs regular watering to maintain leaves; especially in a
pot. In a container, feed regularly during warm weather.
Soil requirements: Most soils will do; use a fast draining potting soil for containers.
Pruning: Not necessary.
Traditional uses: Milky latex used as anthelmentic; chopped leaves and young stem is a fish poison. Dried stems used as fuelwood. Also used as torches. Can be used as live fences and as contour hedges for soil conservation. The tribals, especially Bhil and Saharia of Kota district (Rajasthan, India), use the latex as an adhesive. This species has been used in Ayurvedic and Yunani medicine.
Propagation: Stem cutting gets rooted very easily. It branches enthusiastically, and offsets are readily available. If you remove an offset, remember to let it dry for a week or so, letting the wound heal (cuttings planted too soon easily rot before they can grow roots). It is better to wash the cut to remove the latex. It can also be propagated by seeds. The seed can be sown just under the surface in normal seedling trays in a sandy seed mix. Germination usually occurs within 1 - 3 weeks.
Warning: The milky juice causes dermatitis and is very injurious to the eyes. Accidnetal eye exposure to this plant may cause bilateral conjunctivis with corneal ulcerations and iridocyclitis. Pay extreme attention not to get any in your eyes or mouth. Cultivated plants must be handled carefully. If contact is made with this white sap, take care to not touch face or eyes before washing hands with soap and water.