Yaeyama Palm Forest in Ubunduru

An Endemic Palm Found Nowhere Else

The Yaeyama palm is the sole species in its genus, Satakentia, and is endemic to the Yaeyama Islands. Mature trees can reach a height of about 25 metres, with slender grey trunks roughly 30 centimetres in diameter and large pinnate fronds spreading at the top. A distinctive brown leaf sheath and graceful, upright form have earned it international recognition as one of the world's most beautiful palms. Yellow flowers appear from April to June, after which red-orange fruits develop and ripen.

A Surprisingly Recent Scientific Discovery

Although the palm had long been familiar to local residents, who used the timber for tools and the young shoots as a wild vegetable, it was confused with another species, the Ogasawara nopalm, until quite late. The botanist Sumihiko Hatsushima formally described it as a new species in 1963, and in 1969 the American botanist Harold E. Moore established the new genus Satakentia to accommodate it. The genus name honours Toshihiko Satake, a Japanese patron of palm research.

Scale and Density of the Colony

An Environment Ministry survey conducted in 2008 confirmed approximately 1,769 Yaeyama palms within a designated area of about 1.5 hectares. This concentration is remarkable. Past human use of the species—whose edible shoots and useful timber once led to extensive harvesting elsewhere—is believed to have contributed to the disappearance of other natural stands, making the surviving Ubundoru population all the more precious.

A Window into Insular Evolution

Iriomote Island has been separated from the Asian continent for over a million years, allowing distinctive ecosystems and endemic species to evolve in isolation. The Yaeyama palm is one of the most striking botanical symbols of this insular evolution. Protecting the Ubundoru colony means safeguarding a living archive of southern Japan's natural heritage and contributing to the broader conservation of Iriomote's biodiversity, recognised in 2021 as part of the UNESCO World Natural Heritage Site that includes Amami-Oshima, Tokunoshima, the northern part of Okinawa Island, and Iriomote Island.

The Cathedral-Like Stand of Palms

Visitors who reach a vantage point near the colony often describe the sight as resembling the columns of an ancient temple. The slender grey trunks, all rising to roughly the same height, lift their crowns above the surrounding broadleaf canopy, creating a layered, almost architectural view of the forest.

A Cruise Through Japan's Largest Mangrove Forest

The Nakama River basin contains the largest mangrove forest in Japan in terms of both surface area and species diversity, including such species as Sonneratia alba, Bruguiera gymnorhiza, Kandelia obovata, and Rhizophora stylosa. From the river itself you can also catch glimpses of the Yaeyama palms standing high on the slopes—a memorable view that combines two of the area's most famous natural treasures in a single panorama.

The Giant Sakishima Suonoki Tree

A short walk from the upstream boat landing brings visitors to the Nakama River Sakishima Suonoki, a tree of estimated 300 years of age, listed as one of Japan's "100 Forest Giants." Its dramatic plank-like buttress roots, evolved to stabilise the tree in soft riverside soil, are one of the most photographed natural sights in the Yaeyama region.

Recommended Way to Visit

The most accessible option is to board a Nakama River sightseeing cruise from Ohara Port (the eastern ferry port of Iriomote Island). The cruise glides through the mangroves, allowing the Yaeyama palm colony to be observed from the river. Tickets are typically sold at Shop Jugon near Ohara Port. Departure times vary with the tides, since the river is shallow at low water, so it is wise to confirm the day's schedule in advance.

Getting to Iriomote Island

Iriomote Island is reached by high-speed ferry from Ishigaki Port on Ishigaki Island. Ferries to Ohara Port (the eastern port closest to the Nakama River) take about 35 to 45 minutes. Ishigaki itself is reached by direct flight from Tokyo (Haneda or Narita), Osaka, Nagoya, or Naha.

Tips for an Enjoyable Visit

• Always use a licensed guide or a registered cruise operator. The river is environmentally sensitive and protected by a local conservation agreement.
• Bring insect repellent, long sleeves, and water in any season.
• Iriomote's weather changes quickly; a light rain jacket is useful even on sunny mornings.
• Avoid touching or removing any plants, animals, or soil, as the entire area lies within a national park and World Heritage zone.

Yubu Island

Just off the eastern coast of Iriomote, Yubu Island is reached by a leisurely water buffalo cart that crosses the shallows at low tide. The island is a botanical garden of tropical plants and a gentle introduction to the Yaeyama landscape.

Komi Sakishima Suonoki Colony

Near the mouth of the Maera River, the Komi colony of Sakishima suonoki trees is another designated National Natural Monument. The dense plank-rooted forest is one of the most distinctive sights of southern Japan.

Hoshitate Nature Conservation Area

On the western side of Iriomote, this protected area also contains a Yaeyama palm stand alongside mangrove and ferns, offering a complementary perspective to Ubundoru.