Abstract:
The purpose of this research is to study variation of plant name in some sub-dialects of Northern Thai, Northeasthern Thai, Central Thai and Southern Thai in order to find out how similar or different the plant name in these sub-dialects are, and to conclude from such findings the relationship among the dialects and the sub-dialects. Data were collected from eight informants one in each of following provinces : Chiang Mai, Phrae, Loei, Ubon Ratchathani, Phra Nakhon Si Ayutthaya, Rayong, Surat Thani and Songkhla. The total number of semantic units in this research is 174. The study shows that in studying variation of plant names, the names should be divided into two parts : the pre-core part and the core part. Each part has its own pattern of variation. The variation of each part can explain the relationship among the dialects and sub-dialects in a different way. The variation pattern of the pre-core part suggests that the dialects may be divided into two groups : those in the upper part of Thailand i.e. Northern and Northeasthern Thai, and those in the lower part i.e. Central and Southern Thai. It also suggests that Northern and Northeastern thai have a closer relation ship with Central Thai Than Southern Thai. The variation pattern of the core part shows that NorthernThai is the most distant from the other dialects. In addition, the variation patterns of both the pre-core part and the core part show that the sub-dialects of the same dialect are more closely related than the sub-dialects of the different dialects. It was also found that the sub-dialects of the same dialects are related to the sub-dialects of the other dialects at about the same level except the sub-dialects of Northern Thai.