Campus-Wide Floristic Diversity of Medicinal Plants in Indian Institute of Technology-Madras ( IIT-M ) , Chennai

The floristic diversity of plants and their abundance were analyzed in 2.5 km campus to explore their medical importance by random sampling. The results for plant diversity in IIT-M campus showed nearly 100 species of flowering plants, with genera belonging to nearly 40 families. The most dominant family in the present study is Fabaceae with 15 species (25%) of the medicinal trees. In addition, the dominant medicinal herbs belong to the families of Acanthaceae, Apocynaceae, Fabaceae and Rubiaceae containing 4 species (12%) each. The identified medicinal tree and herb are verified with Red data book to explore their conservation status of every identified medicinal trees and herbs. On comparison with the existing IUCN red data list, the conservation status of 73% of trees and herbs identified in the present study were not assessed. Also, the biodiversity of plants focused on ethano-botanical aspects to reveal their medicinal uses.


Introduction
Biodiversity plays a key role in the livelihoods of tribes and other people to meet their needs in day-to-day life.The plant kingdom is directly connected with human beings from the beginning of its origination in the universe [1].India is one of the vast biodiversity-rich countries in the world where the medicinal plants

Materials and Methods
The institute campus area has a wide distribution of medicinal plants which was made as the main objective of the present study.The distribution of these medicinal plants/tree were identified the aid of taxonomists from Dept of Botany, Alagappa university by referring to authentic literature of the regional flora web database developed by the Prakati Wildlife club of IIT-Madras, Chennai and cross verified with "The flowering plants of Madras city and its immediate neighborhood" [3].An effective analysis has been performed to identify the available medicinal plants along with their distribution and their medicinal uses.

Ethano Botanical Survey
The ethno botanical survey was carried out by wild life club volunteers of IIT-Madras, between august and September 2016.This study covered total vegetation of the area with emphasis on the ethno botanical hotspots of IIT-Madras campus.
Figure 1.Percentage habitat wise distribution of overall vegetation.

Overall Diversity of Vegetation
Thirty-six per cent of the non-cultivated plants species are trees.Excluding cultivated trees such as papaya, lime, sapota, etc., that are rarely found outside gardens and homesteads, 107 species of trees are present on the IIT-M campus.The greater presence of tree species has rendered the vegetation type as a forest.

Over All Diversity of Medicinal Trees/Herbs
298 species of non-cultivated plants were identified on the campus.The numbers may increase between 350 -400 species while including the garden plants.
36% of the non-cultivated plants on the campus are trees.However, of the trees only 40% are native.The higher contribution to the diversity of native flora was rose from the grasses (100%), climbers (84%) and herbs (80%).107 sps., of plants, are non-native.Among these 9 species were invasive.Prosopis juliflora is the most invasive plant on the campus.50% to 60% of the trees in the wilderness zone were dominated by this species.Both tree and herb specimens were collected and identified using regional flora.The collected plant specimen's family and species were confirmed with community herbarium, MS Swaminathan Research Foundation, Chennai.

Calculation of Shannon Index of Species Diversity and Species Richness
The species diversity of medicinal trees and herbs were calculated using Shannon diversity index [4].It has a combination of two quantifiable measures like species richness and species accountability.Higher in numbers of a species denotes wide range of diversity, Shannon-Wiener diversity Index is defined and given by the following function: MATLAB program was created to calculate the Shannon index.[5].

Determination of Conservation Status of Plants and Herbs
The universal conservation status of identified trees and Herbs were determined by IUCN red data list cross verification.

Result
The results on the survey of the plant diversity in the IIT-M campus showed nearly 100 species of flowering plants (both trees and herbs).Among these, 100  2 and Table 1 & Table 2.   Shannon-Wiener diversity index of species richness (H) for the medicinal tree is 4.263 and evenness (E) is 0.972, whereas in medicinal herb species richness (H) was calculated as 3.284 and evenness (E) was 0.975 (Figure 3).
In addition to the floristic study, the present study enumerated the medicinally important plants in the study area which are used to cure different diseases.
Totally 107 medicinal tree and herbs were identified in the wide campus.Of which 73% of trees and herbs are not assessed in IUCN red data list (Figure 4).

Conclusion
The primitive societies of India have been dependent on herbal medicines over a long period of time.In fact, all conventional systems of herbal based therapy had

Figure 2 .
Figure 2. Percentage distribution of (a) medicinal trees and (b) herbs.

Figure 3 .
Figure 3. Shannon graph diversity of species richness index of Trees and Herbs in the study area.

Figure 4 .
Figure 4. Conservation status of (identified in IITM campus) Tree species reported for medicinal purposes in India according to IUCN Red List.NA: Not yet Assessed; LC: Least Concern; NT: Near Threatened; VE: Vulnerable; LR: Lower Risk; EN: Endangered; DD: Data Deficient.
belonged to 40 families.The most dominant family in the present study was Fabaceae with 18 species (25%).Next to that, Moraceae comprises 7 species (9%), Malvaceae include 6 species (8%).The dominant medicinal herbs are from American Journal of Plant Sciences Acanthaceae, Apocynaceae, Fabaceae and Rubiaceae contain 4 species (12%), and Convolvulaceae, Euphorbiaceae, Phyllanthaceae, and Vitaceae are second dominant with 2 species (4%) each.The overall habitat is dominated by Trees in the campus (36 %).The detailed investigation of family in the present study and their medicinal values in a different area is represented in Figure

Table 1 .
Diversity of trees on campus.
(b) American Journal of Plant Sciences

Table 2 .
Diversity of medicinal plants on campus.
NA: Not yet Assessed; LC: Least Concern; NT: Near Threatened; VE: Vulnerable ; LR: Lower Risk; EN: Endangered; DD: Data Deficient.American Journal of Plant Sciences