1. Onogahara and Odamiyama districts in Ehime prefecture, Shikoku are formed of limestone and chert Pareozoic). The former is the only karst topography in Shikoku, where the various plant communities are developed. The latter is mainly formed of chert, and the large area of it is covered with forests. 2. In Komatsugaike, a small pond of Onogahara, Nympaea japono-koreana-Brasenia purpurea community is developed. 3. Swamps are found here and there in Onogahara, where Scirpus wichurui f. borealis-Carex maculata community is usually recognized. Sphagnum community also occurs at momatsugaide. 4. The extensive area of Onoghara is now covered with Sasa sp. -Miscanthus sinensis community. It is consi ered that the occurrence of this community is due to the destruction of the climax forests in the past. Nowadays, the plantation of Pinus densiflora and Larix kaempferi is found in this area. 5. The greater part of the forests belongs to the deciduous broadleaved forest region. But Tsuga sieboldii is dominant in the lower part than about 1000m above sealevel. The beech forest, a climatic climax of this district, is Fagus crenata-Sasamorpha purpurascens association. As the edaphic climaxes, Chama cyparis obutusa community and Pterocarya rhoifolia community are found respectively on the rocky ridge and along the valley.
