49 Nepal is known as one of the richest countries for biodiversity, and almost all the climatic zones of the earth are represented within its national boundary (Hara and Williams, 1978; 1979). The World Conservation Monitoring Center have estimated that 6,500 species of angiosperms are found in Nepal (Caldecott et al., 1994; Bista et al., 2001). Out of the estimated 6,500 flowering plants, approximately 1,000 species are trees. Nearly, 200 species attain tree size and are capable of producing timber (Bhargava and Kumar, 1977). Wood is the cell-wall material produced by the cells of the cambium in a living tree. Wood cells make up the xylem portion of the tree as contrasted with the phloem (bark), which forms the protective outer layer. During the growing season, the cells of the cambium divide frequently into so called daughter cells which may differentiate into specialized elements of the phloem or the wood portion of tree trunk (Pandey, 2001). There are both inter and intra specific anatomical variation in plants (Noshiro et al., 1995). Changing of wood parameters along the elevational gradient was reported from some other studies too which can help to identify the wood at species-level (Pathak, et al., 2011, 2018). Timber, the wood of commercial importance, is one of the most valuable and versatile raw materials used by people, and plays a vital role in the economic and industrial development of a nation. Timber identification is a highly specialized and fascinating field of study which is very complicated to even wood anatomist. Identification of timber may be grouped broadly into two heads, viz. general features and anatomical features. The former include common physical properties like color, weight, hardness, luster, etc. with the help of which simple carpenters and timber dealers also can identify the common timbers. The latter, on the other hand, can be studied only under the microscope and require a minimum basic knowledge regarding the structure of wood for their proper understanding and application in the field of identification of timbers (Pathak, 2012). Botanical knowledge of important timber plants is necessary to identify them in their crude form when they are illegally traded, exported or smuggled. Those are either identified through anatomical study, DNA analysis, and staple isotope analysis or through chemical analysis. Chemical test is one of the general tools to confirm the wood of tree species. Some tools are made to identify the commercially important tree- wood through chemical test or even with the help of ultraviolet rays (BSI, 2012). However, we need to be aware about the use of pesticides and flame retardants because of the chemical substances used. We should be equally aware that the wood sample is actually a solid piece of wood or a manmade composite or plastic made to imitate wood. In this study, we have tried to find out simple chemical reactions to identify some important timbers that are often brought to the National Herbarium and Plant Laboratories of the Department of Plant Resources (DPR) for their identification. Materials and method The wood powders of twenty four wood samples (triplicate samples of each tree) were made with Short Note Wood identification of some important timbers through chemical test M. L. Pathak1*, R. Acharya2, K. K. Pokharel3 and D. Lamichhane1 1. National Botanical Garden, Godawari-3, Lalitpur, Department of Plant Resources, Ministry of Forests and Environment, Nepal. *E-mail: scientistdrmitra@gmail.com 2. National Herbarium and Plant Laboratories Godawari, Department of Plant Resources, Ministry of Forests and Environment, Nepal 3. Forest Research and Training Centre, Ministry of Forests and Environment, Nepal Banko Janakari, Vol 30 No. 1, 2020 Pp 49‒53https://doi.org/10.3126/banko.v30i1.29182 Banko Janakari, Vol 30 No. 1 50 Pathak et al. the help of a saw, and were mixed with water and different chemicals (Alcohol, Sulphuric Acid, Nitric Acid, Acetic Acid, Ether, Ammonia solution, Potassium Chlorate, Sprit, etc.). For the whole study, the BSI 2012 method was partially followed, and some innovative ideas were created. The chemical reactions of wood powder and chemical reagents were observed for twenty four hours. The results of the preliminary reactions were noted down instantly while the final results were obtained after twenty four hours. The study was accomplished during the lab experiment of wood samples at National herbarium and Plant Laboratories from 2011 to 2019. Results and discussion The results of the chemical tests of wood powders and different chemicals are presented in Tables 1−8. In the first phase of our study, only the color obtained from chemical reaction is presented. In the second phase, the chemical reactions and resulted compound with color will be studied in detail. Out of the eight tree-timbers studied, only the wood-powder of Dalbergia sisoo reacted with water and dissolved slightly, and formed suspension at bottom initially yielding slightly pale yellow color after 24 hours. Similarly, the wood powder of Pterocarpus santalinus reacted with Ethyl Alcohol yielding red blood color both at initial and final stages. On the other hand, the wood powder of Santalum album reacted with Ethyl Alcohol yielding black suspension at bottom. The wood powders of the rest seven tree-timbers did not show any reaction with ethyl alcohol. On the contrary, the wood powders of P. santalinus, P. marsupium, S. album, Acacia catechu, Dalbergia sisoo, D. latifolia, Shorea robusta and Terminalia alata reacted with concentrated Sulphuric Acid yielding deep purplish black suspension or black color at the top initially and after 24 hours as well. Similarly, the wood powders of P. santalinus and S. album reacted with Conc. Nitric Acid yielding yellow color after 24 hours while the wood powder of Accacia catechu with Nitric Acid yielded pale yellowish color after 24 hours. Likewise, the wood powders of A. catechu and S. album with Conc. Nitric Acid yielded pale yellowish red color and yellow color, respectively with brown suspension at the top at the beginning and turned into green color after 24 hours. On the other hand, the wood powder of P. marsupium with Concentrated Nitric Acid yielded black suspension at the top initially and turned into green color after 24 hours. Similarly, the wood powders of S. album and A. catechu with Concentrated Nitric Acid yielded yellow color and pale yellowish color initially and pale yellowish red color after 24 hours. The wood powder of P. santalinus with Acetic Acid yielded deep red color initially and turned into deep orange red color after 24 hours. In the case of S. album, A. catechu, P. marsupium, D. latifolia, S. robusta and T. alata, the wood powders did not show any reaction with Acetic Acid. However, the wood powder of Pterocarpus. santalinus with Ammonia solution yielded violet color initially and later too while that of Santalum album yielded red color with suspension at the bottom. The wood powder of Acacia catechu with Ammonia solution yielded black color with suspension at the bottom. On the other hand, the wood powders of P. marsupium and D. latifolia with Ammonia solution did not show any reaction. However, the wood powder of D. sissoo with Ammonia solution yielded yellowish suspension at the bottom at the beginning and finally turned into violet color at the bottom. The wood powder of S. robusta with Ammonia solution remained intact at the bottom initially, and finally turned into violet color with suspension at the bottom. For some genus, we tried to find out the possible chemical reactions between the wood powder and the chemical used; In the case of Shorea robusta, heartwood extractives (brown color) leaching out when in contact with water (Richter and Dallwitz, 2000). Likewise, the chemical ‘santalin’ (C15H14O5) reacts with ethyl alcohol (C2H5OH) and yields red color (BSI, 2012). Nevertheless, the details of reactions among all wood powders (their chemical compounds) and studied reagents could not be traced out. Banko Janakari, Vol 30 No. 1 51 Pathak et al. Table 1: Pterocarpus santalinus (Raktachandan) S.N. Activities Initial result Result after 24 hrs. I Wood Powder + Water (H2O) No reaction No reaction II Wood Powder + Ethyl Alcohol Soluble with red blood color Red blood color III Wood Powder + Acetic Acid Deep red Deep orange red color IV Wood Powder + Conc. H2SO4 Insoluble with deep purplish black suspension at top Insoluble with deep purplish black suspension at top V Wood Powder + Conc. HNO3 No color Yellow color after 24 hours VI Wood Powder + Ether Soluble with yellow color Soluble with yellow color VII Wood Powder + KClO3 Purple color Purple color VIII Wood Powder + NH3 Soluble with violet color Soluble with violet color Table 2: Santalum album (Shreekhanda) S.N. Activities Initial result Result after 24 hrs. I Wood Powder + Water (H2O) No reaction No reaction II Wood Powder + Conc. H2SO4 Dissolved with black color Dissolved with black color III Wood Powder + Acetic Acid No reaction No reaction IV Wood Powder + Conc. HNO3 Dissolved with yellow color Dissolved with yellow color V Wood Powder + Ethyl Alcohol Dissolved and makes black suspension Dissolved with black suspension VI Wood Powder + NH3 Red color with suspension Red color with suspension Table 3: Acacia catechu (Khair) S.N. Activities Initial result Result after 24 hrs. I Wood Powder + Water (H2O) No reaction No reaction but suspension at bottom II Wood Powder + Ethyl Alcohol No reaction No reaction III Wood Powder + Acetic Acid No reaction No reaction IV Wood Powder + NH3 Black color Black suspension V Wood Powder + Conc. H2SO4 Black color Black suspension VI Wood Powder + Conc. HNO3 Pale yellowish color Pale yellowish red color Table 4: Pterocarpus marsupium (Bijayasal) S.N. Activities Initial result Result after 24 hrs. I Wood Powder + Water (H2O) No reaction No reaction II Wood Powder + Ethyl Alcohol No reaction No reaction III Wood Powder + Acetic Acid No reaction No reaction IV Wood Powder + NH3 Undissolved Undissolved both at top and bottom V Wood Powder + Conc. H2SO4 Black suspension at top Black suspension at top VI Wood Powder + Conc. HNO3 Brown suspension at top Color changed into green Banko Janakari, Vol 30 No. 1 52 Pathak et al. Table 5: Dalbergia latifolia (Satisal) S.N. Activities Initial result Result after 24 hrs. I Wood Powder + Water (H2O) No reaction No reaction II Wood Powder + Ethyl Alcohol No reaction No reaction III Wood Powder + Acetic Acid No reaction No reaction IV Wood Powder + NH3 Undissolved Undissolved both at top and bottom V Wood Powder + Conc. H2SO4 Black suspension at top Black suspension at top VI Wood Powder + HNO3 Undissolved Orange color Table 6: Dalbergia sisoo (Sissoo) S.N. Activities Initial result Result after 24 hrs. I Wood Powder + Water (H2O) Slightly dissolved with suspension at bottom Slightly pale yellow color II Wood Powder + Ethyl alcohol No reaction No reaction III Wood Powder + NH3 Yellowish suspension at bottom Violet color at bottom IV Wood Powder + Conc. HNO3 Dissolved with orange red color Yellow suspension at bottom V Wood Powder + Acetic Acid Not dissolve suspension at bottom Slightly pale yellow suspension at bottom VI Wood Powder + Conc. H2SO4 Black suspension at top Whole black suspension at bottom Table 7: Shorea robusta (Sal) S.N. Activities Initial results Result after 24 hrs. I Wood Powder + H2O (Water) Undissolved with suspension at bottom Brown suspension at bottom II Wood Powder + Ethyl Alcohol Undissolved with suspension at bottom Suspension at bottom III Wood Powder + NH3 Remained same at bottom Violet color suspension at bottom IV Wood Powder + HNO3 Reddish brown suspension at top Red black color suspension at bottom V Wood Powder + Acetic Acid suspension at bottom suspension at bottom VI Wood Powder + H2SO4 Black suspension at top Whole black suspension VII Wood Powder + Spirit Undissolved with suspension at bottom Suspension at bottom Table 8: Terminalia alata (Asna/Saaj) S.N. Activities Initial results Result after 24 hrs. I Wood Powder + Water (H2O) Undissolved with suspension at bottom Suspension at bottom II Wood Powder + Alcohol Undissolved with suspension at bottom Suspension at bottom III Wood Powder + Acetic acid Not dissolve remain at bottom Suspension at bottom IV Wood Powder + NN3 Suspension at bottom Changes into violet color V Wood Powder + H2SO4 Black suspension at top Black suspension both at top and bottom VI Wood Powder + HNO3 Black suspension at top Turned into yellow color Banko Janakari, Vol 30 No. 1 53 Pathak et al. Conclusion It was found that different timber wood samples yielded different color due to formation of dissimilar compounds. It proves that chemical test is also an important tool to distinguish or identify the close species of a genus besides anatomical and DNA methods, and it will be helpful to recognize plants for taxonomic identification and illegally traded, exported or smuggled wood samples. We have realized that it would be more effective if we could describe the exact compounds formed after reactions, but it is not an easy task. As far as possible, we will accomplish this task in the second phase of our study. Acknowledgements The authors are thankful to the Director General and Deputy Director General of the Department of Plant Resources together with the Chiefs of the National Herbarium & Plant Laboratories and National Botanical Garden for their constant encouragement in course of the study period. References Bhargava, A. K. and Kumar, S. (1977). Timber trees of Nepal. Van vigyan 15 : 23−27. Bista, M. S., Adhikari, M. K. and Rajbhandari, K. R. (eds. ) (2001). Flowering plants of Nepal (Phanerogams). Bulletin of the Department of Plant Resources No. 18. His Majesty's Government of Nepal, Department of Plant Resources, Kathmandu, Nepal. BSI (2012). Pharmacognosy of negative listed plants. Botanical Survey of India, Ministry of Environment and Forests, Government of India. Caldecott, J. O., Jenkins, M. D., Johnson, T. and Groombridge, B. (eds. ) (1994). Priorities for conserving global species richness and endemism. World Conservation Monitoring Center, World Conservation Press, Cambridge, UK. Hara, H. and Williams, L. H. J. (eds. ) (1978). An enumeration of the flowering plants of Nepal. Vol. I. British Museum (Natural History), London. Hara, H. and Williams, L. H. J. (eds. ) (1979). An enumeration of the flowering plants of Nepal. Vol. 2. British Museum (Natural History), London. Noshiro, S., Suzuki, M. and Ohba, H. (1995). Ecological wood anatomy of Nepalese Rhododendron (Ericaceae) : Inter-specific variation. Journal of Plant Research 108 : 1–9. DOI : 10. 1007/BF0234434 Pathak, M. L., Shrestha, B. B., Joshi, L. and Jha, P. K. (2011). Variation in length of vessel element and fibre of two species of Rhododendron along the attitudinal gradient in eastern Nepal. Bulletin of the Department of Plant Resources 33 : 47−55. Pathak, M. L. (2012). Wood identification manual of important timbers of Nepal. Vol I. Government of Nepal, Department of Plant Resources, National Herbarium and Plant Laboratories, Godawari, Lalitpur, Nepal. Pathak, M. L. Shrestha, B. B., Joshi, L., Gao, X. F. and Jha P. K. (2018). Anatomy of two Rhododendron species along the elevational gradient, Eastern Nepal. Banko Janakari 28 (2) : 32−44 Pandey, B. P. (2001). Plant Anatomy. S. Chand and Company Limited, Ramnagar, New Delhi-110055. Pathak, M. L., Shrestha, B. B., Joshi, L. and Jha, P. K. (2011). Variation in the length of vessel element and fiber of two Rhododendron species along the altitudinal gradient in the Eastern Nepal. Bulletin of the Department of Plant Resources 33 : 67−71. Richter, H. G. and Dallwitz, M. J. (2000 onwards). Commercial timbers : descriptions, illustrations, identification, and information retrieval. In English, French, German, Portuguese and Spanish Version, 25th June, 2009. http : //delta-intkey. com /wood/en/ index. htm.