Included here is the Ryukyu Archipelago situated between Kyushu and Japan, and comprising Okinawa, Ishigaki, Iriomote, Tokuno-Shima, and the Amami and Tokara islands.

Ryukyuan Broadleaved Evergreen Forest

On Okinawa much of the natural forest has been badly disturbed but there are still good stands on some islands, for example, on Iriomote. Here the dominant tree species are Castanopsis sieboldii, Distylium racemosum, Michelia compressa var. formosana and Quercus miyagii, beneath which is a diverse shrub layer of species like Ardisia sieboldii, Daphniphyllum teijsmannii, Lasianthus cyanocarpus, Psychotria rubra, Randia canthioides and Sysygium buxifolium. The tree fern flora is very diverse with species such as Alsophila pustulosa, Cyathea fauriei, Gymnosphaera denticulata and G. podophylla. There are also many lianas including Epipremnum mirabilis, Flagellaria indica, Freycinetia formosana, Smilax china var. kuri and epiphytes such as Gastrochilus japonicus,  Neottopteris australasica and Psilotum nudum. Other ferns include Abacopteris triphylla, Bolbitis koidzumii, Colysis pothifolia, Diplazium virescens, Lindsaea chienii, Rumohra aristata and Tectaria phaeocaulis.

Ryukyuan Pine Forest

The main pine species is the endemic Pinus luchuensis (Pinaceae) and ranges from Akuseki in the north, through the Amami Islands, Okinawa and to Iriomote in the south. It tends to occur in disturbed areas.

References

Numata, M. (ed). 1974. The flora and vegetation of Japan. Elsevier Scientific Publishing Company.

Numata, M., Miyawaki, A. & Itow,  D. 1972. Natural and semi-natural vegetation in Japan. Blumea, 20: 435-481.