Saraca asoca– morphology and diversity across its natural distribution in India

Abstract

Trees play a chief role in the existence of human civilization. We get a glimpse of the trees that have to be planted at a site in Varahamihira's Brihat Samhita. In Brihat Samhita tank bunds are discussed to be shaded with Mangifera indica, Terminalia arjuna, Ficus religiosa, Ficus benghalensis, Syzygium cuminii, Mitragyna parviflora, Borassus flabellifer, Madhuca longifolia, Mimusops elengi, and Saraca asoca 1 .Saraca asoca or Jonesia asoca Roxb., commonly known as Ashoka, is a medicinal tree used to treat gynecological problems, as found in records of Charaka Samhita, Bhavprakasha Nighantu, and the treatise of Susruta 2-4 . Belonging to the genus Saraca, it comes under the Fabaceae family.The genus Saraca includes Saraca asoca (Roxb.) De Wilde, Saraca indica Linné, Saraca thaipingensis Cantley ex Prain, Saraca celebica De Wilde, Saraca griffithiana Prain, Saraca hullettii Prain, Saraca declinata (Jack) Miq., and Saraca dives Pierre, to name a few 5 . Of these, S.asoca (Roxb.) de Wilde, S.indica L., S.declinata Miq. (Red Saraca) and S.thaipingensis Prain (Yellow Saraca) has been reported in India. While S.asoca grows in the wild, the other three are grown in botanical gardens. [6][7] Though mainly used for ornamental purposes, they possess immense medicinal values. 7 Ashoka is a perennial evergreen tree, growing to a height of 10m. 9 Though a native of the Indian sub-continent, it is also seen in Sri Lanka and the Indo-Malaysian region. In India, Ashoka trees are found in Peninsular India, comprising the Western and Eastern Ghats and the sub-Himalayan tracts, to an altitude of 750m. It also prefers to grow in semi-evergreen and moist deciduous forests and is found along river streams. 10,11 Red lateral alluvial soil is suitable for growth and requires an annual rainfall of 2000-4000mm. 12 Saraca asoca (Roxb.) de Wilde, though known as Ashoka, has many common names in different languages -Ashoka in Hindi, Kankeli in Sanskrit, Ashokadamara in Kannada, Ashokapatta in Telugu, Asokam in Malayalam, and Asogam in Tamil. 13 It is considered a 'sacred tree' by both Hindus and Buddhists and holds high significance and importance in mythology, literature, and history. 2 The first variety of Ashoka -Aswani-I -with high bark yield and more tannin content has been released through a single plant selection method. 14 Other than 'Ashokarishta' and 'Ashokaghrita' many tablets, tonics, and syrups made from S.asoca are available in the market like 'Ashotone', and 'Ashonil'. 10 The Ayurvedic formulation of Ashokarishta comprises of Saraca asoca bark, Woodfordia fruticosa flower, Cuminum cyaminum fruit, Cyperus rotundus rhizome, Zingiber officinale rhizome, Berberis aristata stem, Nymphea stellata flower, Terminalia bellirica fruit pericarp, Terminalia chebula fruit pericarp, Phyllanthus emblica fruit pericarp, Mangifera indica endosperm, Adhatoda vasica root, Santalum album heartwood, and jiggery. 15 The bark helps in stopping excessive menstrual bleeding and hemorrhagic dysentery due to the presence of tannins. 16 Chemical investi...