on Calotropis ( Wara ) : Is it a miracle shrub or just a plant ?

Apocynaceae Juss. (The Angiosperm Phylogeny Group, 2016) commonly called as the dogbane family, comprises 357 genera and about 5100 species (Nazar et al., 2013) of flowering plants including herbaceous or shrubby climbers (Wong et al., 2013; Chan et al., 2016: Lu et al., 2014). The Calotropis (Wara, hela-wara in Sinhala and errukalai, manakkovi, mannakovi, urkkovi in Tamil) which is a small genus belongs to this family consisting of two species, Calotropis gigantea (L.) R. Br. and C. procera (Aiton) Dryand. Calotropis is a succulent and xerophytic shrub or small laticiferous tree up to 2.5 m, commonly known as “milkweed” or “Crown flower” (Kumar et al., 2011; Hindi, 2013; Wong et al., 2013; Muriira et al., 2015; Moustafa and Sarah, 2017). The stem usually simple and branched at the base, woody covered with a corky bark, leaves simple, opposite, sub-sessile, white and purplecolored flowers and not scented (Sharma, 2011; Joseph et al., 2013). Inflorescence is a dense, multiflowered, umbellate cyme, highly cross-pollinated through insects such as monarch butterflies, simple, follicle fruit (Endress et al., 2007; Joseph et al., 2013). Following figure shows the purple and white colored flowers and follicle fruit of Calotropis found in Sri Lanka. Calotropis species are most diverse in tropical and subtropical parts of Asia and South East Asia (Bangladesh, Cambodia, Burma, China, India, Indonesia, Malaysia, Pakistan, Philippines, Sri Lanka and Thailand) and extend into temperate areas (Nasser et al., 2012; Nazar et al., 2013). Calotropis is a versatile tree used for different purposes. The importance of Calotropis can be explained: (a) uses of the plant in traditional medicine (b) research performed on the isolation of compounds and their scientific value (c) commercial values of the plant. (a) Uses of the plant in traditional medicine

Apocynaceae Juss. (The Angiosperm Phylogeny Group, 2016) commonly called as the dogbane family, comprises 357 genera and about 5100 species (Nazar et al., 2013) of flowering plants including herbaceous or shrubby climbers (Wong et al., 2013;Chan et al., 2016: Lu et al., 2014. The Calotropis (Wara, hela-wara in Sinhala and errukalai, manakkovi, mannakovi, urkkovi in Tamil) which is a small genus belongs to this family consisting of two species, Calotropis gigantea (L.) R. Br. and C. procera (Aiton) Dryand. Calotropis is a succulent and xerophytic shrub or small laticiferous tree up to 2.5 m, commonly known as "milkweed" or "Crown flower" (Kumar et al., 2011;Hindi, 2013;Wong et al., 2013;Muriira et al., 2015;Moustafa and Sarah, 2017). The stem usually simple and branched at the base, woody covered with a corky bark, leaves simple, opposite, sub-sessile, white and purplecolored flowers and not scented (Sharma, 2011;Joseph et al., 2013). Inflorescence is a dense, multiflowered, umbellate cyme, highly cross-pollinated through insects such as monarch butterflies, simple, follicle fruit (Endress et al., 2007;Joseph et al., 2013). Following figure shows the purple and white colored flowers and follicle fruit of Calotropis found in Sri Lanka. Calotropis species are most diverse in tropical and subtropical parts of Asia and South East Asia (Bangladesh, Cambodia, Burma, China, India, Indonesia, Malaysia, Pakistan, Philippines, Sri Lanka and Thailand) and extend into temperate areas (Nasser et al., 2012;Nazar et al., 2013). Calotropis is a versatile tree used for different purposes. The importance of Calotropis can be explained: (a) uses of the plant in traditional medicine (b) research performed on the isolation of compounds and their scientific value (c) commercial values of the plant.
In Bangladesh by folk medicinal practitioners use leaves for treatment of high blood sugar and pain. Research carried out by Haque et al., (2012) strongly showed that of leaves of C. gigantea is a potential source of obtaining newer anti-hyperglycemic and anti-nociceptive drugs for treatment of pain and high blood sugar levels in diabetic patients. The roots of

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Editorial Journal of the University of Ruhuna, Sri Lanka 6(2), 2018 the plant is reported to have properties of pregnancy interceptive (Srivastava et al., 2007).
Mosquitocidal, larvicidal and pupicidal properties of medically important mosquito vector species; Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus have been studied (Neraliya and  Srivastava, 1996;Moustafa and Sarah, 2017). A study revealed the ethanol extract of leaf of C. gigantea is an ideal eco-friendly approach for the control of vector (Kovendan et al., 2012). A decoction of leaf along with soap is an effective remedy for white ants (Ranade and Acharya, 2014). Stem of this plant possess hepato-protective effects as demonstrated by protection of liver of rats against carbon tetrachloride induced liver injury, effects against hepato-carcinogenesis without any harmful effects in treated animals (Wong et al., 2013). Toxic effect of Calotropis on the heart and testis of male albino rats has been tested, proven high toxicity and recommended the use of Calotropis as rodent control without leaving harmful chemical traces (Moustafa and Sarah, 2017).

(c) Commercial values of the plant
Due to its potential economic importance, Calotropis has been introduced to the Pacific Islands, Australia, as well as to Central and South America as an ornamental plant (Maji et al., 2013;Hindi, 2013;Joseph et al, 2013, Payal andSharma, 2015). Calotropis stem and seed coat produces fine, white, silky, durable, strong, cylindrical, flexible and highquality fibre which has created great interest in many countries for industrial applications; useful for making ropes, carpets, fishing nets, cheap cots, gunny bags, bow strings, in the manufacture of paper, pulp, duplicating stencils, sewing threads ( . The white, strong and silky floss which is from the fruit (seed capsules) is used as an inferior stuffing material in mattresses and pillows as well as for weaving into a strong cloths, shawls, handkerchiefs, packing material since it is too short and too light for spinning (Ranade and Acharya, 2014;Payal and Sharma, 2015). The floss may also substitute cotton wool for surgical purposes (Akhtar et al., 2014).
The seed oil can be used for soap, paint and making varnish and oil cake is used as manure (Ranade and Acharya, 2014). In Thailand, the flowers are used in wedding ceremonies, various floral arrangements in temples and in rosaries (Gaur et al.,201). Ruminant (sheep, goats, and camels) are fed with other feeds which are mixed with chopped leaves of Calotropis (Payal and Sharma, 2015). Calotropis is a good source of green manure which can help to improve soil water conditions and also acts as a soil binder and mulching (Gaur et al., 2013;Payal and Sharma, 2015;dos Santos et al., 2017;Fanish, 2017). Wood is used in making charcoal and cooking fuel (Gaur et al., 2013;Nasser et al, 2012;Hindi, 2013).
Plants often escape from cultivation, especially when growing on sandy soils (near to sea beaches and coastal areas). This precious plant is able to propagate and thrive in harsh conditions of heat, drought and poor soils, high salinity and water logging wastes, fallow lands, rubbish heaps, roadsides, sand dunes and arable lands in different environments (Meena et al., 2010;Hindi, 2013). Moreover, this plant has a high level of regeneration potential and could be harvested up to 4 times a year. Calotropis often self-sows freely on overgrazed land and has been used as an indicator of exhausted soil. Due to its ability to accumulate heavy metals, natural elements (Uranium) from different soils and an abandoned mining site, Calotropis has several ecological roles: serves as natural phytoremediation, improves the quality of soil, rehabilitates abandoned and exhausted lands and brings back life once again (Moustafa and Sarah, 2017).
The liquid latex, a rubber-like product can be used as a renewable source of valuable hydrocarbons and intermediate energy resources which may be utilized to convert into diesel substitutes (Erdman and Erdman 1981;Shilpkar, 2007: Moustafa andSarah, 2017). Due to free from NOx gases, SO2 and Suspended Particulate Matter (SPM) and high cetane value, the bio-diesel derived from Calotropis may be a good source of renewable energy (Payal and Sharma, 2015). Therefore, Calotropis may be a potential plant for bioenergy and biofuel production in these areas where Calotropis grow. (Payal and Sharma, 2015;Moustafa and Sarah, 2017).

Future areas of the research
As a conclusion, scientists, relevant authorities and other stakeholders have not paid attention on this wonderful and amazing plant present in Sri Lanka. Therefore, further researches are necessary to elucidate the phytochemical and pharmacological aspects of this plant to look forward the therapeutic aspects, development of new drugs from Calotropis for the control and combat the various diseases.
Because of its high adaptability to severe environments, invading abilities, researchers consider this valuable plant as a weed or an invasive plant and are looking for controlling strategies. Instead of destroying, considering the numerous benefits and Journal of the University of Ruhuna, Sri Lanka 6(2), 2018 products of the plant in different facets (eco-friendly solutions to pollution, to fulfil the demand of fibre for textile industry, energy limitation and habitat degradation problems, etc.), this valuable and fastgrowing tree species can be utilized to overcome these problems. Jain, A., Katewa, S.S., Sharma S.K,, Galav, P., Jain, V., (2011) Snakelore and indigenous snakebite remedies practised by some tribals of Rajasthan.