13th Flora of Thailand Meeting


Scientific programme day 1


Tuesday, 12th July


Chairperson Professor John Parnell
Botany Department, Trinity College Dublin


Biodiversity and Biogeography of Peninsular Thailand
Kyle Williams, Stuart Davies & David Middleton


Kyle WilliamsAbstract Thailand is one of the most botanically diverse countries in the world with an estimated 12,000 vascular plant species. The southern Peninsula of Thailand spans nearly eight degrees of latitude (5?N-13?N) and includes the transition zone between the Indo-Burmese and Sundaland floristic regions, two of the six most diverse and threatened biodiversity hotspots in the world. It has been estimated that over 500 genera of plants have their northern or southern distributional limits within the transition between these floristic regions. Various explanations for why these floras became and remain distinct have been proposed, including the role of the strong rainfall seasonality gradient that occurs within the Peninsula. However, analyses of biogeographic patterns have not been possible due to a dearth of plant collections from the Peninsula. Thailandís average of only 50 herbarium specimens/100 km2 pales in comparison to countries such as the United Kingdom (1720 specimens/100 km2), and is even low compared to other areas of Southeast Asia (e.g., Java and the Malay Peninsula each average nearly 200 specimens/100 km2). The principle objective of this new project is to create an inventory of the plants of Peninsular Thailand through intensive field collection and collation of existing records. In addition to testing biogeographic hypotheses on the Peninsula flora, this inventory will be used to create an interactive, computerized, web-accessible key to the families and to selected genera of the Peninsula . It is expected that numerous new country and regional distributional records will be made, as well as the discovery of many taxa new to science. Plant inventory data derived from this project will also be used for the broader Flora of Thailand project, and will form an important resource for critical conservation initiatives in the Peninsula.


Endemic and rare plants in Thailand: biogeographical aspects
Rachun Pooma


Rachun PoomaAbstract Biogeographically, Thailand lies between the Indochinese and Sundaic (Indomalay) regions, and is considered a collective centre of botanic diversity from three regional elements: Indo-Burmese, Indo-Chinese, and Malesian. As a result, Thailand shares its flora with many neighbouring countries; the number of true endemics is, therefore, not high. However, the BKF database and flora publications showed that many taxa have been found within restricted areas, including true cases of endemism for the country. These particular biogeographic zones are reviewed and focused on for the study of endemic and rare plants in Thailand.


A taxonomic revison of the genus Phyllanthus L. (Euphorbiaceae) in Thailand
Pranom Chantaranothai


Pranom ChantaranothaiAbstract Phyllanthus in Thailand is revised and 39 species are recognised. Phyllanthus chayamaritae and P. isanensis are described as new. Phyllanthus microcarpus is reinstated. Phyllanthus brunelii and P. winitii are placed in synonymy of P. microcarpus and P. sootepensis, respectively. The following 10 species are typified: Phyllanthus minutiflorus, P. album, P. anamensis, P. angkorensis, P. collinsiae, P. glaucifolius, P. geoffrayi, P. harmandii, P. pulcheroides and P. taxodiifolius. Six species: Phyllanthus airy-shawii, P. chayamaritae, P. isanensis, P. kerrii, P. orientalis and P. sootepensis are endemic to Thailand. Three species: Phyllanthus caroliniensis, P. cathetus and P. harmandii are new to Thailand. Distributional and ecological information, vernacular names and a key to species are provided.


Chairperson Dr. Kongkanda Chayamarit
Forest Herbarium, Thailand


Flora of Thailand grasses - a collaborative account
David Simpson & Kongkanda Chayamarit


David SimpsonAbstract The grasses represent the second largest family of Monocotyledons with 700 genera and 10,000 species worldwide, of which 133 genera and 505 species are present in the Thai flora. The economic importance of grasses is well known and they play a dominant role in many natural and human-influenced ecosystems. A summary of the major groups occurring in Thailand and their uses will be presented. Completion of the Flora account is a major undertaking. The Flora of Thailand Grasses project commenced in June 2004 and aims to finish the account by June 2009. The team comprises 14 contributors, mostly from Thailand, spread across 11 institutes. The project represents an ideal opportunity to encourage young Thai botanists to undertake Ph.D. and postdoctoral level research in systematics as well as making an important contribution to the Flora of Thailand.

The genus Premna L. (Lamiaceae) in Thailand

Charan Leeratiwong


Charan LeeratiwongAbstract The purpose of the taxonomic study of the genus Premna is to provide a complete revision of the genus for Thailand. Twenty-five species are covered (Premna annulata, P. collinsae, P. corymbosa, P. cordifolia, P. coriacea, P. dubia, P. flavescens, P. fulva, P. garrettii, P. herbacea, P. interrupta var. smitinandii, P. latifolia, P. nana, P. paniculata, P. pyramidata, P. quadridentata, P. racemosa, P. repens, P. scandens, P. serrata, P. siamensis, P. trichostoma, P. villosa, Premna sp. 1 and Premna sp. 2), of which, 7 are endemic to Thailand and two are new species which have been circumscribed. Within Thailand, the Northern region contains 22.5 % of the species, with 3 out of 16 which occur in this area being endemic. Most species occur in primary evergreen forest, especially in the rocky areas. Provisional work suggests that calyx characters may be taxonomically important allowing classification of this genus into 4 major groups.


The Eriocaulaceae of Thailand
Amornrat Prajaksood & John Parnell


Amornrat PrajaksoodAbstract An anatomical study of the Eriocaulaceae of Thailand was undertaken using permanent slides of transverse sections of leaves and scapes (inflorescence axis) of a representative, forty-three species. Sixty anatomical characters were recorded. Keys were constructed mainly using anatomical characters of the scape. Twenty binary state characters were found to be of possible value for phenetic and cladistic analyses. The anatomical dataset was initially compiled using EXCEL. The dataset was imported into, and phenetic analysis performed using, SPSS 12.0.1 for Windows (furthest neighbor method and simple matching coefficient). The dendrogram from the phenetic analysis suggested that the 43 species could be divided into 3 groups. 11 characters, 7 characters and 5 characters were shared within Groups I, II and III, respectively. However, parsimony analysis performed using PAUP version 4.0b8 (heuristic search) only supported Group I from the phenetic analysis with a bootstrap percentage support of 57%. Morphological and molecular studies of the family are continuing.


Progress in the revision of Poaceae subtribe Setariinae in Thailand
Monton Norsangsri, Pranom Chantaranothai & David Simpson


Monton NorsangsriAbstract Poaceae are one of the larger families in the Flora of Thailand comprising 505 species in 133 genera. A preliminary taxonomic account of subtribe Setariinae in Thailand is presented. Nineteen genera, 102 species and 12 infraspecific taxa are enumerated and described. Panicum (19 species), Urochloa (12 species) and Setaria (10 species) are the three largest genera from this subtribe in Thailand. Two new taxa are reported and three taxa are newly recorded for the country. The talk will highlight some of the main features of the group.


A review of the Begoniaceae in Thailand
Martin Sands


Martin SandsAbstract In addition to the 33 published Thailand species of Begonia, assigned to six sections of the genus, it is estimated, currently, that at least a further ten species await description. In this presentation, the distinguishing characters of the sections will be discussed and the morphological variation of the species reviewed. The distribution of the species within the country as well as wider geographical range and habitat variation will also be considered.


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