Among the different hills in Tumakuru district, the plant diversity is highest at Sidderbetta with 378 spp., of which 94 species are collected exclusively from this hill and are not found to occur in other parts of the district. Interestingly, among these, there are a number of wild relatives or progenitors of present day cultivated plants and is home of several rare and interesting plants which are restricted to Siddarabetta such as Aphyllorchis tumukurensis (a new species of saprophytic orchid), Curcuma neilgherrensis, Zingiber zerumbet are among others. It is also known to be a treasure house for medicinal plants with over170 species (nearly 50 per cent) occurring in this hill are known to be having medicinal value, of which 48 species have good potential, 41 moderate and 81 low potential medicinal plants. In view of its richest plant diversity with largest number of medicinal plants Siddarabetta should be declared as a ‘Medicinal plant heritage site’.
Siddarabetta in Koratagere taluk, is the tallest (1272.12 metres) hillock in Tumakuru district, popularly known for its rich assemblage of medicinal plants and from time immemorial it is known to be a treasure house for medicinal plants. Over 170 species (nearly 50 per cent) occurring in this hill are known to be having medicinal value. There are instances of several important dignitaries camping in this hill station to get themselves relieved from ailments by using the plants growing there. There is a story which explains why this hill range is home to many valuable medicinal plants: Mythologically it is believed that Hanuman, who was sent by Rama to fetch the life-giving Sanjeevini herb to revive the unconscious Lakshmana, uprooted the entire Sanjeevini hill. On his way to Lanka, he dropped a part of the hill, which grew into Siddarabetta. With this background, a study was made to checklist the flora and especially the medicinal plants of Siddarabetta.
Intensive plant explorations were undertaken in Tumakuru district, including Siddarabetta, during 1985 – 1988 and subsequently stray collections were made till 2015. Specimens were processed and preserved in the Herbarium, University of Agricultural Sciences, Bengaluru (UASB). Plants were collected from foot hill, shorea grove, slopes and valleys and hill tops. Specimens were identified using mainly the Flora of British India by Hooker (1904) Flora of Presidency of Madras by Gamble (1915), the Flora of Presidency of Bombay by Cooke (1901), in addition to a number of local district floras of Karnataka. The medicinal uses of plants collected were ascertained from Thakur et al. (1989), ‘Medicinal Plants of Karnataka’ by Keshava Murthy (1994), Yoganarasimhan (1996) and also based on the local people’s indigenous knowledge.
Among the different areas in Tumakuru district, the plant diversity is highest at Sidderbetta (378 spp.) with a total area of c.1156 ha, followed by Devarayanadurga (303 spp.) in a total area of c. 4227 ha, Bukkapatna (118 spp.) in an area of c. 34,824 ha and Manchaladore (126 spp) within a total area of c. 2500 ha. There are other isolated hills like Sowndenahalli beat (c. 1000 ha), Ramadevarabetta (c. 400 ha), Huliyurdurga (c. 200 ha) which have small area under forests but are also rich in species diversity but not as much as in Siddarabetta.
From the present study it is found that Siddarabetta is the largest biodiversity centre in the entire district. In all, 378 species of flowering plants have been collected and identified from Siddarabetta alone, of which 94 species are collected exclusively from this hill and are not found to occur in other parts of the district (Table 1). Interestingly, among these, there are a number of wild relatives or progenitors of present day cultivated plants such as Atalantia racemosa (wild lemon), Canavalia cathartica (wild sword bean), Vigna trinervia, Macrotyloma uniflora (wild relatives of pulses), and is home of several rare and interesting plants which are restricted to Siddarabetta such as Aphyllorchis tumukurensis (a new species of saprophytic orchid), Curcuma neilgherrensis, Zingiber zerumbet, Zephyranthes, Crotalaria prostrata, C. pulcherrima, C. sandoorensis, Desmodium motorium, Mucuna pruriens, Rhynchosia hirta, Pogostemon benghalensis, Utricularia praeterita, Chlorophytum malabaricum, Rotala densiflora, Ximenia Americana, Opilia amentacea, Habenaria sp., Ventilago denticulata, Wendlandia thyrsoidea, Allophylus cobbe, Gmelina arborea, Aganosma cymosa, are among others.
The distribution of medicinal plant species in Sidderbetta varies among the four different habitats classified based on distinct altitudinal, edaphic and biotic factors. The altitude ranges from 750 metres at the foot of the hill to 1272 metres at the top of the hill. Such a habitat differentiation has shown that of over 150 medicinal plants recorded from Siddarabetta, 126 are habitat specific and occur only in one type of habitat while twenty plants occur in three out of four habitats.
(Written by Mr. V. Bhaskar and Mr. C.G. Kushalappa, for more details, please download the Karnataka Forest Department's, 'My forest' Journal (September - December 2015), from aranya.gov.in)
