13th Flora of Thailand Meeting
Poster session
Chromosome study of selected Argostemma species (Rubiaceae)
Saitip Apinyanan, Ladda Aksomtrameth, Kitichate Sridith
Abstract: New information on the chromosomes of selected species in the genus Argostemma Wall. (Rubiaceae) has been obtained. Most have the same chromosome number: 2n=22. The relationships between species in the genus due to the chromosome number and karyological characters are discussed. It is suggested that Argostemma Wall. might remain a “good genus”. However, more information on chromosome numbers together with the karyotype patterns of some selected species would be needed in order to support the relationships between various taxa in the genus.
The Genus Polyalthia Blume (Annonaceae) in Thailand
Pasakorn Bunchalee & Pranom Chantaranothai
Abstract: The genus Polyalthia Blume (Annonaceae) in Thailand is revised. Twenty-eight species and three varieties (31 taxa) are recognized. Three species are newly recorded in the country; Polyalthia corticosa, Polyalthia lateritia and Polyalthia meghalayensis. Acetolysed and unacetolysed pollen of 11 taxa were investigated using both light and scanning electron microscopy. The pollen can be divided into five types based on exine sculpturing.
The taxonomy of the family Rhamnaceae in Thailand
Pranom Chantaranothai & Monton Norsaengsri
Abstract: A study of Thai Rhamnaceae recorded 10 genera, 36 species and 41 taxa. Two genera, Sageratia and Scutia, and five species, namely Smythea pacifica, Ventilago gladiata, Ventilago leiocarpa, Ventilago oblongifolia, and Zizyphus kunstlei are newly recorded from Thailand.
The biodiversity of the Flora of Ba Vi National Park
Le
Tran Chan
Abstract: Study of the flora of Ba Vi National Park has largely been limited to inventories of species composition or finding the number of medicinal plants. This study analyses the biodiversity of the flora of Ba Vi National Park based on three basic characteristics of the flora - viz: systematic structure, life-form spectra and geographic element spectra. Systematic structure: There are 1,173 species, 570 genera, 139 families belonging to 6 high-vascular plant phyla. The Pteridophyte group comprises 6 phyla: Psilotophyta, Equisetophyta, Lycopodiophyta, and Polypodiophyta, and includes 15 families, 37 genera, and 95 species, accounting for 11% of total number of families, 6.4% of the total number of genera and 8.1% of the total number of species of the flora. The majority of the families (119 families or 85.6%), genera (528 genera or 92.6%) and species (1.078 species or 91.9%) belong to the Angiospermae phylum. The Gymnospermae phylum includes only 5 families (3.6%), 5 genera (1% ) and 6 species (0.4%). This composition is similar to that of the Vietnamese flora. Calculation shows that, the flora of Ba Vi National Park has a genus coefficient of 2.0; and family coefficient of 4.1. On average, each family includes 8.4 species affirming the richness of the flora in terms of family, genera, and species. These coefficients are closely related to the area of the studied flora: as the area increases, these coefficients increase. Of the 1,978 species of Angiosperms in the flora of Bavi National Park 893 species are Dicotyledones and 185 species Monocotyledones. So, the percentage of the total number of species in Dicotyledones class in comparison with Monocotyledones class is 4.8. This is the highest percentage among the floras that have been studied in Vietnam. The ten most abundant families in the flora of Ba Vi National Park are in descending order: Rubiaceae – 70 species, Euphorbiaceae – 56 species, Poaceae – 50 species, Cyperaceae – 47, Compositae – 45, Moraceae – 38, Fagaceae – 30 species, Lauraceae – 30 species, Papilionaceae – 30, and Urticaceae – 30 species. In total, there are 426 species from the ten families richest in species, accounting for 36.3% of the total number of species of the flora. Life-form spectra: Using the classification framework of Raunkiaer, we have identified and sorted 1.173 high-vascular plant species by 5 life-form groups. The result indicates that, the dominant group is the Phanerophytes (with about 51% of the total number of species), next is the Hemicryptophytes (with 25% of the total number), and last is the Therophytes (1/15 of the total number of species of the flora). Geographic element spectra: We have also built-up a system of geographic elements for the flora of Ba Vi National Park, based on the published works on current distribution space of the species – our system consists of 18 elements. We have not taken into account the origins of those species. 1,173 species found have been arranged into 18 geographic elements: the Bacbo endemic element, Vietnam endemic element, Indochina element, Southern Chinese element, Hainam–Taiwan–Phillippines element, Himalaya element:, India element, Malaysia element, Indonesia–Malaysia element, Malaysia- Indonesia-Australia, Tropical Asia element, Palaeotropical element, Neotropical and circumtropical element, East Asia element, Asia element, Northern temperate element, the widely disposing element and finally, the Modern migrant and imported elements.
Khaosokia caricoides, a new genus and species of Cyperaceae from Thailand
David Simpson, Muthama Muasya, Kongkanda Chayamarit, John Parnell, Somran Suddee, Bart De Wilde, Michael Jones, Jeremy Bruhl & Rachun Pooma
Abstract: Khaosokia caricoides, D.A. Simpson, Chayam. & J.Parn., a newly discovered genus and species of Cyperaceae is described and illustrated. The genus is characterised by a narrowly paniculate dioecious inflorescence with 2–4 nodes, each of the nodes having a leaf-like inflorescence bract that exceeds the inflorescence. Spikelets in both sexes are linear-cylindric and each flower has seven perianth bristles. The nutlet was immature in the specimens examined. The photosynthetic pathway is C3. Khaosokia is endemic to limestone cliffs in peninsular Thailand; its conservation status is assessed as Vulnerable (VU B1a + 2a). It has affinities to tribes Cariceae, Dulichieae and some members of Scirpeae, but the exact nature of these relationships has yet to be determined.
Vines in Sakaerat Wild
Sarawood Sungkaew & Atchara Teerawatananon
Abstract: A one year expedition concentrating on the vines in ca. 78 km2 of Sakaerat Biosphere Reserve (Sakaerat Wild), Northeastern Thailand, was conducted during July 2002 to June 2003. About 200-270 vine species were estimated to exist in the wild in “Sakaerat Wild”. However, by means of random survey, it was found that there are 94 species from 79 genera of 40 families. Of four habitats, it is dry evergreen forest which possesses the highest species diversity, with 77 species. The following habitats and species diversity are; mixed deciduous forest (70 species), dry Dipterocarp forest (44 species), waste places and roadsides (26 species) respectively.
Plant community Succession in Check Dam at Tuplan National Park of Thailand
Sompong Thammathaworn, S. Ratree, T. Koprasit
Abstract: The main objective of this work was to investigate the seasonal dynamics of the vegetation in checked dam (study sites). The study site is situated in Tuplan National Park, Northeastern Thailand. This study was carried out to determine which plant species occurred in the sample site. Environmental factors of the area etc. light intensity, air temperature, soil temperature, soil moisture, and soil pH, were measured every month from April 2001 to March 2002 in order to cover all wet and dry seasons. Samples of plant species were collected from nine check dam in order to confirm the correct botanical name. Pioneer species showed xerophytic characters which included leaves and stems covered with hairs, a thick cuticle or the presence of thorns. Sedges and related species etc. Cyperus spp., Scirpus spp. appeared dominant in the wet seasons, whereas xerophytic species etc. Imperata cylindrica Beauv., Chromolaena odorata (L.) R.M. King & H. Rob., Hyptis suaveolens Poit., Eupatorium adenophorum Spreng., Passiflora foetida L, Croton spp., Euphorbia hirta L. and Aganosma marginata G. Don were found both in wet and dry seasons. All nine sample sites were in the area of open grass-land. Light intensity was in the range of 2000-29,000 lux; mean temperature of the warmest month was 24oC in the shade and 37oC in the open-air. Soils were well-drained, a friable sandy loam, high in iron with red and brown subsoils forming natural aggregates (peds) when disturbed. Soil moisture from the dry season was 15-25%, pH was 5-6, humus was low, and soils thin. High evaporation rates and low precipitation reduced leaching of the soil.
A new type of silica cell in the genus Dictyospermum Wight (Commelinaceae)
Thaweesak Thitimetharoch, Robert B. Faden & Achra Thammathaworn
Abstract: Silica cells were studied using leaf scraping, whole-mount clearing, paraffin transverse section, scanning electron microscopy, energy dispersal X-ray analysis system, and the hydrofluoric acid test. A new type of silica cell which varies from 40-150 ?m in top view of the adaxial epidermal cells and 30-80 ?m in side view of the adaxial epidermal cells, is reported here for the first time and uniquely distinguishes the genus Dictyospermum Wight. Silica component tends to deposit at trichomes.
Leaf anatomy of Poaceae subtribes Ischaeminae and Rottboelliinae in Thailand
Paweena Traiperm, Thaweesakdi Boonkerd, Pranom Chantaranothai & David Simpson
Abstract: Leaf anatomy of 15 species in eight genera of Poaceae subtribes Ischaeminae and Rottboelliinae in Thailand was investigated using epidermal peels and transverse sections. Features regarded as particularly distinctive include the morphology of the wall of intercostal cells, the shape of subsidiary cells and silica bodies, macro-hairs, papillae, prickles, the position of the stomata, midrib and keel bundles, rib and furrows on the adaxial surface, the shape and distribution of bulliform and colourless cells, and the type of bundle sheath cells. It is shown that leaf anatomy provides characters which are taxonomically useful in classification at generic and specific levels.
The vegetation of Doi Phuwae in Nan Province Thailand
Chusie Trisonthi
Absrtact: Doi Phuwae is a limestone mountain located in Nan Province, where the marine gastropod fossils have been found. The vegetation of this area is similar to Doi Luang Chiangdao in Chiangmai Province. The striking plants found are Trachycarpus oreophilus, Mahonia siamensis, Buddleja macrostachya, Selaginella tamarisina, Viola sp., Siline burmanica etc.
The genus Hedyotis L. in Thailand
Khanit Wangwasit & Pranom Chantaranothai
Abstract: The genus Hedyotis L. in Thailand is studied. For this study, Hedyotis s.s. and Oldenlandia L. are treated under Hedyotis s.l. Forty nine species and three varieties are enumerated. The pollen morphology of 10 species were examined by light and scanning electron microscopy. All grains were monads, isopolar, radial symmetry and 3-6-colporate. The pollen grains were 10-33 ?m. Five differentiated exine sculpturing patterns were observed: foveolate, perforate, psilate-reticulate, regulate and scabrate.
Progress in the Cucurbitaceae for the Flora of Thailand
Willem de Wilde & Brigitta Duyfjes
Abstract: The Cucurbitaceae is pan-tropical with about 120 genera and 850 species. In Thailand there are about 25 genera and 60 species. There are 2 subfamilies. Since the last Flora of Thailand meeting in 2003 pre-cursory revisions of 4 essential genera have been published: Neoalsomitra, Trichosanthes (a genus of ca. 80 species of which nearly 20 are found in Thailand), Zehneria s.l. and Solena. Far advanced for publication are reviews of: Mukia, Cucumis, Gymnopetalum and Gynostemma. Taxonomic problems still have to be solved in Thladiantha and Zanonia and in the Hemsleya – Gomphogyne – “Cirromitra” (nov. gen. in sched) complex. The genus Zehneria, as conceived for Thailand (Thai Forest Bulletin 32: (2004)), has to be reconsidered as it seems to represent several different genera, for a large part sustained by phylogenetic analysis of DNA studies. A brief explanation of the new division will be presented and representatives of most genera will be shown during the presentation. For the Flora of Thailand treatment of Cucurbitaceae three keys to the genera will be proposed: one scientific key and two practical keys for male flowering and female flowering (and fruiting) specimens. The treatment is scheduled for 2007.