สำนักงานราชบัณทิตยสภา

The Journal of the Royal Institute of Thailand Volume IV - 2012 49  ( ทิพเกสร )’; the sky blue to mauve blue tulip-shaped fl owers ‘Sarassa Chandhorn ( สรัส จันทร )’; and the compact white globose fl ower heads ‘Manee Dheva ( มณีเทวา )’. The wet wild fl ower fi eld or ‘seasonal blanket marsh vegetation’ in the northeast can be categorized ecologically as a type of seasonal wetland comprised of diverse fl ora, mainly herbaceous plants, grasses and sedges. This unique vegetation habitat is characterized by an extensive blanket-like layer of wet organic soils or substrates overlaying fl at sandstone rock formations or ‘Phalanhin’ on the exposed fl oor of deciduous dipterocarp forest. After a long, hot and wet rainy season, cool breezes start to blow at the onset of the cold season and a variety of small fl owering herbs profusely carpeting the wet ground fl oor come to life again. Their small, delicate and colorful fl owers will soon competitively blossom, spreading their vivid fl oral beauty across the wide fi elds. The main fl oristic components of these wild fl ower fi elds belong to the carnivorous genera of Sarai Khaonieo ( สาหร ายข าวเหนียว )- Utricularia spp. (Lentibulariaceae) and Yad Namkhang ( หยาดนํ าค าง - Drosera spp. (Droseraceae), the mycotrophic to autotrophic genus of Dokdin ( ดอกดิน )- Burmannia spp. (Burmanniaceae), and the other common genera of Kadum Ngoen ( กระดุมเงิน )- Eriocaulon spp. (Eriocaulaceae) and Yabua ( หญ าบัว )- Xyris spp. (Xyridaceae). The height of the plants in full bloom varies from 7 to 25 cm, or rarely up to 40 cm, depending on topography, amount and distribution of rainfall, temperature, fi re frequency, presence of dominant species and some other biotic factors. As regards the existing wet grassy habitat, climate, soil and soil water are the main interacting environmental factors that in fl uence the distribution of these plants and plant communities. The seasonal wetland vegetation, as exempli fi ed by the wet wild fl ower fi eld Lan Dusita, is commonly encountered in the areas where precipitation and the stream draining water in the rainy season are their main water supplies. The soils in the wet fi eld become temporarily water-saturated after heavy rain. Following the week-long blooming period, the substrates dry out and the plants completely wither and turn straw-colored in the hot dry season. Thawatchai Santisuk