Illustrated Manual on Tree Flora of Kerala Supplemented with Computer-Aided Identification
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KFRI Research Report No. 282 ISBN No. 0970-8103 ILLUSTRATED MANUAL ON TREE FLORA OF KERALA SUPPLEMENTED WITH COMPUTER-AIDED IDENTIFICATION N. Sasidharan Non-Wood Forest Products Forest Utilisation Programme Division K F R I Kerala Forest Research Institute An Institution of Kerala State Council for Science, Technology and Environment (KSCSTE) Peechi - 680 653, Kerala, India July 2006 CONTENTS Acknowledgements ............................................................................................ Abstract .............................................................................................................. 1. Introduction.......................................................................................... 1 2. Review of literature ............................................................................... 1 3. Study area ........................................................................................... 3 3.1. Location.................................................................................................. 3 3.2. Geology and soil...................................................................................... 3 3.3. Climate................................................................................................... 4 3.4. Vegetation............................................................................................... 4 4. Methodology ......................................................................................... 8 5. Results and discussion ....................................................................... 10 6. Systematic treatment.......................................................................... 12 7. References ........................................................................................ 501 ACKNOWLEDGEMENTS The guidance, advice and the moral support and above all, the interest shown by Dr JK Sharma, Director and Dr R Gnanaharan, Research Co-ordinator, KFRI are acknowledged with due respect. The financial support for the study by the Ministry of Environment & Forest, Govt. of India, New Delhi is gratefully acknowledged. The identity of many doubtful specimens was confirmed by referring to authentic specimens at Madras Herbarium, Coimbatore and with the Cibachromes from Kew Herbarium. I am particularly thankful to Dr M Sanjappa, Director, Botanical Survey of India; Dr GVS Murthy, Joint Director, Southern Circle, Botanical Survey of India, Coimbatore; Dr P Lakshminarasimhan and Dr SK Srivastava, former and present IBLO, Kew for granting permission to refer herbarium and for the Cibachromes of type specimens. I received help from various Institutions and Individuals. They include Mr. DK Ved and Dr K Ravikumar, FRLHT, Bangalore; Dr D Narasimhan, Madras Christian College, Chennai; Dr M Sivadasan, Dr AK Pradeep and Dr M Sabu, Calicut University; Dr N Anil Kumar, MSSRF, Kalpetta; Dr K Kishore Kumar, GGVHSS, Feroke; Dr Jomy Augustine, St. Thomas College, Pala; Dr MK Janarthanan, Goa University. Almost all Project staff in the NWFP Discipline, KFRI helped me in one or other way during the study and I am thankful to P Sujanapal, KR Deepthi, VP Thomas, V Suresh, Amitabachan, Dr TD Babu, Sreekanth Sreedhar, Willy George and PD Sanjith. The services Shri Subash Kuriakose and Shri VB Sajeev for photography of some of the trees and illustrations are also acknowledged with thanks. MM Roy developed the Computer Aided-Identification Program. I appreciate his whole- hearted co-operation. I am thankful to the Kerala Forest Department, particularly to Shri PK Surendranathan Asari, IFS, former Principle Chief Conservator of Forests for granting permission to collect specimens and photography. Finally, I also place on record my sincere thanks to Shri Ashok Bhatia, Additional Director and Dr JR Bhatt, former Additional Director, Ministry of Environment & Forests and Dr R. Gadagkar, Chairman, for the Committee of the projects, for their help, criticisms and suggestions. Abstract Identification of trees at sight is often required by Biologists, Ecologists, Foresters et al. This cannot be achieved with conventional floras, where identification keys are invariably based on floral and vegetative characters. Therefore a Computer-aided identification program (TreeID) was developed exclusively on easily observable field and vegetative characters which are always present, except for the short leafless period of deciduous trees. The TreeID is a menu driven Multi-entry key and all characters are of equal value and one need not follow the sequence or order followed in the case of dichotomous keys. Pictures of all key characters used in the identification program are provided for easy selection and comparison and one need not get familiarised with the so called “botanical jargons” for identifying trees. Photographs depicting diagnostic features of trees such as bark, blaze, leafy twigs with flowers, fruit, etc. are provided for easily comparing with the matching characters and confirmation. Therefore, the chance of misidentifying the trees included in the TreeID is rather remote. Search facility is provided to find out family, genera and species. There is also provision to find trees based on local/trade names. A help menu is provided in the CD on how to use the TreeID The Manual and the Computer-aided Identification Package deal with 650 trees attaining a height of 4 m or more with a clear bole. The 650 trees include 72 common exotics, introduced as agricultural, forestry or ornamental/avenue trees. One hundred and fifteen trees belong to the Red Listed Categories and many of them are known only by their type collections made a centaury ago. We were able to locate most of the Red Listed trees. Two new trees discovered during the study are named as Humboldtia sanjappae and Stereospermum colais var. shendurunii (in press). In the Manual Dichotomous parallel keys based on generative and vegetative characters are provided for the identification of families, genera, species and infraspecific taxa. The correct botanical name with author(s) name and citation are provided with basionym and synonym(s), if any. References to monographs/revisions and floristic studies in Kerala are cited. Local name(s) are also given, if known. Description, habitats (vegetation wise), geographical distribution and District-wise occurrence in Kerala are provided along with flowering and fruiting periods. The species belonging to Red Listed categories are indicated to the IUCN (1994) category to which they are assigned. 1. Introduction The Western Ghats region comprising the forests of Kerala has been recognised as one of the bio-diversity centres in India. The estimated number of flowering plants in Kerala constitutes nearly one-fourth of the total 17,000 flowering plants of India. Among the flowering plants of Kerala, 20 per cent are trees and 30 per cent of them are Western Ghats endemics. Since the publication of Forest Trees of Travancore (Bourdillon, 1908), there has been no serious attempt to study the tree flora in detail. Identification of trees in tropical forests has always been a challenge. The height of the trees, inconspicuous flowers, short flowering period, etc. make the task more difficult. This resulted in the poor representation of specimens of tree species in the National and Regional Herbaria. They are often represented by the type specimens or the ones collected by Forest Botanists like Beddome, Bourdillon, Barber, et al. made a centuary ago. The poor representation and lack of recent collections prompted Botanists to consider several trees as rare and threatened. Identification of trees at sight is often required by Foresters, Wildlife biologists, Ecologists, et al. Botanists traditionally follow the Linnaean style of delimiting taxa based on floral characters and often ignore field and vegetative characters which are more helpful in the identification. Hence, Botanists are now giving importance to field characters for identification of trees. Field keys have been developed for field identification of trees (Balasubramanian et al., 1985; Pascal & Ramesh, 1987). One of the ‘weaknesses’ of plant taxonomy has been the excess use of technical terms in the identification keys and description of species, which makes the conventional floras more useful only to Botanists. Computer-aided multi-entry identification keys are very convenient than conventional dichotomous keys. Nowadays, Laptop computers are used by field Biologists for identification of plants. Therefore a study was undertaken to prepare a Manual on the Tree Flora of Kerala and a Multi-entry Computer-aided Identification Program to ease the identification of trees in the field as well as in the laboratory. The Ministry of Environment and Forests, Govt. of India granted financial support for the study. The Computer-aided package for the identification of trees of Kerala is exclusively based on vegetative and field characters such as bark, bole, buttress, blaze, exudation, branching pattern, thorns, prickles, leaves, etc. to make it more user friendly. 2. Review of literature Coloquis dos Simples (Garcia de Orta, 1565), a checklist on the medicinal plants of India, is the first published Botanical work on the plants of the Western Ghats. Subsequently after a centuary, a more elaborate work on the plants of 1 Malabar coast, Hortus Indicus Malabaricus, was brought out by van Rheede (1678-1703). Major contributions to the floristic studies in India were made by the Britishers. Among the Botanists who worked on the flora