Flowering plants of Agumbe region, central Western Ghats, Karnataka, India

: Agumbe, the Cherrapunji of southern India, is a bastion of rich endemic flora. In the present study of random sampling, a total of 570 species of flowering plants were collected belonging to 370 genera and 105 families, including a few endemic and Red Listed medicinal plants such as Garcinia gummi-gutta (L.) Roxb., Dipterocarpus indicus Bedd., Dysoxylum malabaricum Bedd. ex C.DC., Elaeocarpus tuberculatus Roxb., Hopea canarensis Hole, Calophyllum apetalum Willd., Adenia hondala (Gaertn.) W.J.de Wilde, and Myristica dactyloides Gaertn. Family Leguminosae contributes the maximum number of species (47 species) followed by Rubiaceae (32 species) and Asteraceae (27 species) and Genera Ficus (9 species), Diospyros (8 species) and Syzygium (7 species) are the dominant genera. Trees (185 species) are the dominant species followed by herbs (162 species), climbers (117 species), shrubs (62 species), grasses and sedges (19 species), epiphytes (15 species) and parasites (10 species).


INTRODUCTION
Taxonomic studies and floristic explorations can provide efficient and convenient information regarding the nomenclature, distribution and ecology, utility of various plants species, and about an ecosystem. It is estimated that the tropical forests harbor about 70% of living organisms of the whole world, of which roughly 20% of the total are confined as exclusively endemic throughout the tropical forests (Myers 1988).
India is one among 18 mega biodiversity nations harboring about 4,381endemic species of flowering plants (Nayar, 1996;Shigwan et al. 2000;Singh et al. 2015). Among 35 global biodiversity hot spots (Mittermeier et al. 2011) identified, India has four; including the Western Ghats, which is the second largest endemic centers in India with 1,273 species (Nayar et al. 2014 a,b).
The Western Ghats is one of the two high diversity humid tropical forest tracks in India. The most outstanding feature of the Western Ghats is the formation of tropical rain forests along the windward side facing the Arabian Sea. The tropical climate complimented by heavy precipitation from the south-west monsoon and favorable edaphic factors create an ideal condition for the luxuriant growth of plant life, which can be seen only in a few parts of the world (Gadgil 1996). The tropical forests have received much attention in recent years because of their species richness, high standing biomass, and greater productivity (Denslow 1987). A rainforest is a dense, wet, and tropical evergreen ecosystem, high in its level of biodiversity. One among the tropical rainforests of the Western Ghats is found in the Agumbe region.
According to the Karnataka State Natural Disaster Monitoring Centre (KSNDMC), Hulikal (442m), located more than 244m below Agumbe (686m) area, has received heavy rainfall (more than 125mm) on an average of 4.6 times a year compared to twice a year in Agumbe during the past decade. The reason for the variation of rainfall in Hulikal is the construction of a reservoir, which has created an anthropogenic impact on the environment and the weather system and that has led to heavy rainfall. There has been a change in the temperature, humidity and soil moisture in Hulikal after the construction of the dam (Prabhu 2011).
Agumbe, the Cherrapunji of the south is famous for its endemic flora and medicinal plants (Sundararaghavan 1970). Hence, the present study was conducted with the intention to report the present status of the flowering plant diversity of this region, as there is no updated account available for this ecologically unique and important region.

Study area
The study area is 568ha of tropical low-land evergreen forest of Agumbe (13.5087°N 75.0959°E) in Shivamogga district of Karnataka, India. Agumbe tropical rain forests are the heart of central Western Ghats with a wide range of species composition and floral distribution. These forests are classified as tropical wet evergreen forests of the Dipterocarpus indicus-Humboldtia brunonis-Poeciloneuron indicum type (Pascal 1988). The mean annual rainfall is 7,620mm (300 inches) and the average temperatures vary between 22.2 o C and 23.6 o C with an annual average temperature of 23.5 o C. Agumbe lies in a hilly, wet region of the Western Ghats with an elevation of 643m (2,250ft), canopy cover of 80-85% and lies in a UNESCO World Heritage Site (UNESCO 2011). According to Champion & Seth's (1968) classification, Agumbe is an area of "southern tropical wet evergreen forests". The Agumbe Medicinal Plants Conservation Area (MPCA) was established in 1999 to protect the important medicinal plants of the region (Figure 1).
The study revealed the presence of 162 herbaceous species, in which 160 were ground flora. Among them Asteraceae emerged as the dominant family with 27 species followed by Acanthaceae (19 species), Poaceae (17 species), Lamiaceae (11 species), and Leguminosae (11 species). Many of the herbs were used for various medicinal and edible purposes. Some rarely seen plants like Epipogium roseum, a saprophytic land orchid, shows its emergence for only 15 days in a year with beautiful flowers, but vegetative phases are not seen on the ground.
Due to the dense canopy, only a few numbers of shrubs were observed during the present study. A total of 62 shrubs belonging to 25 families and 52 genera were observed. Among them, Rubiaceae and Acanthaceae emerged as dominant families with 10 and seven individuals, respectively. Species like Ardisia solanacea, Atalantia monophylla (respiratory disorders), Gnidia glauca (mumps), Ixora coccinea (fever), Memecylon malabaricum (herpes), Pavetta   (IUCN 2017). Only 15 species of epiphytes were found in the study area. The majority of the epiphytes belong to Orchidaceae (12), followed by Apocynaceae, Gentianaceae, Gesneriaceae, and Moraceae with one species each, A total of 10 angiospermic parasites were observed and they were seen on varied host plants such as Terminalia paniculata, Terminalia tomentosa, Olea dioica, and Artocarpus hirsutus. Family Loranthaceae with eight species emerged as the dominant family, followed by Convolvulaceae and Santalaceae with one species each (Annexure 1).
Among 570 flowering plants, 58 were considered threatened. Some species which are endangered need to be conserved for the future. These threatened species fall under 34 families, where Leguminosae and Dipterocarpaceae have five species each, followed by Lauraceae with four species and are the dominant families (https://www.iucnredlist.org) (Annexure 2).

DISCUSSION
A comparative analysis of tree diversity in the tropical lowland evergreen forests of Agumbe in three one hectare plots displayed the presence of 3,202 live stems representing 125 species of trees in 92 genera and 42 families (Srinivas & Parthasarathy 2000), whereas in the current study, 195 species of trees belonging to 54 families and 137 genera were observed in all the areas of the rain forests of Agumbe.
Species diversity and density of all woody climbers (lianas) inventoried in three one-hectare plots in the tropical lowland evergreen forest of Agumbe yielded a total of 1,138 lianas belonging to 40 species (Padaki & Parthasarathy 2000). In the current study, a total of 117 species of climbers were found to occur, of which 59 species were lianas.
A floristic survey carried out in Agumbe MPCA by the FRLHT botanical team reported 371 plant species of which 182 are medicinal. Adenia hondala, Celastrus paniculatus, Garcinia gummi-gutta, Myristica dactyloides, Persia macrantha, and Vateria indica are a few threatened species recorded from this area (Nayar & Sastry 1990). The study also revealed the Agumbe MPCA is a genuine storehouse of floristic diversity. The presence of pure stands of Poeciloneuron indicum is a significant character of this forest (Udayan 2003). But, in the current study the whole area of Agumbe rainforest was enumerated and yielded more momentous results than the other studies.
Bhat (2014)  Major threats that are intimidating the diversity  www.threatenedtaxa.org The Journal of Threatened Taxa (JoTT) is dedicated to building evidence for conservation globally by publishing peer-reviewed articles online every month at a reasonably rapid rate at www.threatenedtaxa.org. All articles published in JoTT are registered under Creative Commons Attribution 4.0 International License unless otherwise mentioned. JoTT allows allows unrestricted use, reproduction, and distribution of articles in any medium by providing adequate credit to the author(s) and the source of publication.

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