Main Article Content
Caesalpinia L. is a genus of spiny trees, shrubs, or climbers. There are eighteen species of Caesalpinia reported in Thailand. Besides organoleptic evaluation, the microscopic characterization is additionally used for plant authentication. This study aimed to establish the microscopic leaf characteristics of eight Caesalpinia species in Thailand. The fresh mature leaves of eight Caesalpinia species were collected from three different places throughout Thailand. The midrib transverse sections were investigated under microscope attached with digital camera. The laminae were evaluated for stomatal cells, epidermal cells, palisade cells, and trichomes. The results found that there were unicellular non-glandular trichomes in four species. The trichomes were covering on both dorsal and ventral epidermis of C. digyna Rottler, C. minax Hance and C. decapetala (Roth) Alston whereas C. bonduc (L.) Roxb. found trichomes only at the margin and midrib of both leaf surfaces. Caesalpinia sappan L., C. pulcherrima (L.) Sw., C. mimosoides Lam., and C. coriaria (Jacq.) Willd. were not presented trichome on their leaves. Stomatal cells were presented only on ventral epidermis of all species. Trichome characteristics of C. bonduc could be used as an identification key for this species. Trichome number and trichome index determined from C. minax, C. digyna, and C. decapetala were found to be overlapping. However, upper epidermal cell area was capable to identify C. decapetala. Furthermore, the stomatal number could differentiate C. digyna from C. minax. For non-trichome containing species, C. sappan and C. pulcherrima could be identified by stomatal index and upper epidermal cell area. Microscopic leaf constant numbers between C. mimosoides and C. coriaria were overlapping, however C. coriaria demonstrated its identity due to isolateral character. Microscopic leaf constants evaluation is proved to be one of the methods capable in plant authentication.
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
 T. Smitinand, Flora of Thailand Volume Four Part One, 1984, pp. 65.
 B. Verdcourt, A manual of New Guinea Legumes. 11 (1979) 20-29.
 Y. Pitakpawasutthi, C. Palanuvej, N. Ruangrungsi, Microscopic Leaf Constant Numbers of Chromolaena odorata in Thailand, Pharmacognosy Journal. 10(6) (2018) Supplement Issue: s95-s99.
 U. Niinemets, A. Lukjanova, M.H. Turnbull, A.D. Sparrow, Plasticity in mesophyll volume fraction modulates light-acclimation in needle photosynthesis in two pines, Tree Physiology. 8 (2007) 1137-1151.
 N.R. Lersten, J.D. Curtis, Leaf anatomy in Caesalpinia and Hoffmannseggia (Leguminosae, Caesalpinioideae) with emphasis on secretory structures, Plant Systematics and Evolution. 192 (1994) 231-255.
 B. Mehra, S.K. Maurya, K.N. Dwivedi, Pharmacognostic evaluation of Latakaranja (Caesalpinia bonduc L. Roxb.), International Journal of Green Pharmacy. 9(4) (2015) 63-69.
 C. Martin, B.J. Glover, Functional aspects of cell patterning in aerial epidermis, Current Opinion in Plant Biology. 10(1) (2007) 70-82.
 S.B. Gokhale, C.K. Kokate, A.P. Purohit, Pharmacognosy first year diploma in pharmacy. 29th ed. Nirali Prakashan, 2009.
 G. Komlaga, G.H. Sam, R. Dickson, M.L.K .Mensah, T.C. Fleischer, Pharmacognostic studies and antioxidant properties of the leaves of Solanum macrocarpon, Journal of Pharmaceutical Sciences and Research. 6(1) (2014) 1-4.
 M. Kundu, R. Mazumder, M.D. Kushwaha, G.S. Chakraborthy, Pharmacognostic profiles of leaves of Caesalpinia bonduc L. Roxb., Pharmacologyonline. 3 (2011) 71-77.
 R. Foroughbakhch, R.J. Ferry, J.L. Hernandez-Pinero, M.A .Alvarado-Vazquez, A. Rocha-Estrada, Quantitative measures of leaf epidermal cells as a taxonomic and phylogenetic tool for the identification of Stanhopea species (Orchidaceae), Phyton-International Journal of Experimental Botany. 77 (2008) 113-127.