Taxonomy of Thai Boraginaceae Kanokorn Rueangsawang & Pranom Chantaranothai Applied Taxonomic Research Center, Department of Biology, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand The taxonomy of the Thai Boraginaceae has been revised for the flora of Thailand. A total of 12 genera are recognized comprising 41 species. The genus Argusia, Carmona, Coldenia, Maharanga, Onosma and Rotula are represented by one species each. Twelve species are enumerated in Cordia, three in Cynoglossum, five in Ehretia, seven in Heliotropium, and four species each in Tournefortia and Trichodesma. Two species, Maharanga lycopsioides and Onosma burmanica are categorised as rare species restricted on limestone mountains in northern Thailand. Delimitation of Boraginaceae In 1789 Antonine Laurent de Jussieu published a plant classification system, Genera plantarum. He classified 28 Ehretia Coldenia Rotula genera into three different groups based on the following characteristics; berry-like fruits, one or two-locular capsules Carmona 3 Argusia 6 and four separate nutlets. In 1819 Schrader established a 4 6 segregate family Heliotropiaceae including the genera 6 2 Heliotropium and Tournefortia. Further, Airy Shaw (1973) 1 INTRODUCTION 2 Heliotropium divided the family Boraginaceae into Heliotropioideae and Cordia 6 3 Boraginoideae and accepted a separate family, Ehretiaceae. 6 Tournefortia Many authors such as Hutchinson (1969), Heywood (1993) and 2 Riedl (1997) regard as separate families. Diane et al. (2002) 2 Cynoglossum accepted Heliotropiaceae as a separate family based on 1 2 Trichodesma molecular and morphological study. Maharanga The present study, Boraginaceae in Thailand is regarded as Onosma a family consisting of four subfamilies and 12 genera based mainly on gynoecium characters; Cordioideae (Cordia L.), Boraginoideae Ehretioideae (Carmona Cav., Coldenia L., Ehretia P. Browne, Rotula Lour.), Heliotropioideae (Heliotropium L. and Tournefortia L.) and Boraginoideae (Cynoglossum L. style gynobasic Maharanga A. DC., Onosma L. and Trichodesma R. Br.) Similar in style terminal (Ruengsawang & Chantaranothai, 2009). 1 = habit style bifid 2 = inflorescence style twice 3 = flower style simple 4 = stamens fruit a drupe 5 = style fruit of nutlet 6 = fruit Figure 2. Interrelationships of genera in Thai Boraginaceae. Acknowledgements The author thanks the curators and staff for their facilities, Mr P. Polsena for the photos. This work was supported by the TRF/BIOTEC Special Program for Biodiversity Research and Training, grant BRT R_151001 and the Applied Taxonomic Research Center, Khon Kaen University. References Airy Shaw, H.K. 1973. A dictionary of the flowering plants and ferns, 8th . Cambridge University Press. De Jussieu, A.L., 1789. Genera Plantarum. Herissant & Barrois, Paris Diane, N, Forther, H. and Hilger, H.H. 2002. A systematic analysis of Heliotropium, Tournefortia and allied taxa of the Heliotropiaceae (Boraginales) based on ITS1 sequences and morphological data. American Journal of Botany 89: 287-295. Heywood, V.H., Brummitt, R.K, Culham, A. and Seberg, O. 2007. Flowering Plant Families of the World. Oxford University Press. Hutchinson, J. 1969. Evolution and phylogeny of flowering plants. Academic Press, London. Reidl, H. 1997. Boraginaceae. Flora Malesiana, Series I, 13: 43-144. Ruengsawang, K. & Chantaranothai, P. 2009. A revision of Boraginaceae subfamily Boraginoideae in Thailand. Thai Journal of Botany 1(2): 29-41. Schrader, H.A. 1819. Commentations societatis regiae scientiarum gottingensis recentiores 4: 192. Figures 1. Boraginaceae in Thailand. Sunday, December 11, 2011.