Preserving Biodiversity

Conservation Efforts at the Tsukuba Botanical Garden

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Conservation of endangered plants

The Tsukuba Botanical Garden is making dedicated efforts to conserve numerous endangered plants. Especially, we are focusing on plant taxa (e.g., ferns and orchids) environments (e.g., aquatic) and regions (e.g., the Ryukyus of Japan) that contain many endangered species.



Ferns are seedless vascular plants that propagate through spores. Ferns have been known to exist for about 420 million years, since the Paleozoic Era, and currently, about 10,000 fern species exist on the earth. Approximately 850 species of ferns from eastern Asia to the South Pacific region are grown at the Tsukuba Botanical Garden for research and conservation. The outdoor fern garden features a theme-based display of ferns.

Endangered fern species are mainly grown in Nurseries that is not open to the public. As of January 2009, 77 (39%) of the 197 species of ferns put on the endangered list (2007 edition) by the former Environment Agency (currently reconstituted as Japanese Ministry of the Environment) were being grown here. Of these, five plants belonging to 3 lineages of Dryopteris shibipedis, which was treated as an extinct (EX) species, are being preserved here.

  Greenhouse for fern cultivation in Nurseries, that is not open to the public   Cyrtomium macrophyllum var. microindusium (CR)  

Dryopteris shibipedis (EW)




Orchid (Orchidaceae) is the largest plant family, comprising approximately 25,000 species. Tsukuba Botanical Garden maintains one of the world's largest collections of orchids with approximately 3,000 species for research and conservation. We are propagating endangered species by in vitro seed propagation. On the occasions of annual orchid exhibitions in our facilities, we present educational displays on sciences and arts related to orchids

Ex situ conservation of the orchid collection in the backyard

We simulate various environments in the backyard and grow many species for insurance and founders of reintroductions.

Cymbidium aspidistrifolium

This is an endangered orchid species found in southwestern Japan. It has been recognized as synonymous with Cymbidium lancifolium. However, we found that they are different species.

Malaxis iwashinae

A new species discovered during field surveys conducted by Tsukuba Botanical Garden in the Republic of Vanuatu.

Coryanthes macrantha

Flowers have evolved in many ways in order to attract animals that will carry pollen from one flower to another. Coryanthes macrantha is one example of flowers that have undergone unique adaptations.

Aquatic plants

Approximately 160 species of around 40 families of aquatic plants, including 121 of about 222 Japanese species, are cultivated and conserved at the Tsukuba Botanical Garden.
Aquatic environment is one of the areas where natural habitats are rapidly undergoing destruction both in Japan and overseas. Approximately 41% of all aquatic plants in Japan are faced with the threat of extinction. 49% of these endangered plants are being conserved at the Tsukuba Botanical Garden. One characteristic feature of the Garden's efforts towards preservation of aquatic plants is the creation of growth environments suitable for all aquatic plants from freshwater to brackish and salt water.

Preservation facility of aquatic plants in the nursery Monochoria korsakowii (NT)


Plants in the Ryukyus

The Ryukyu Archipelago (the Ryukyus) consists of about 200 islands spanning an area 1,300 km between Japanese Kyushu and Taiwan. The Ryukyus is known to be an area having high plant diversity and endemism, where threatened plant species can be found. In the Garden, we are performing biodiversity studies – including of evolutional biology, taxonomy, and phylogenetics – using molecular, cytogenetic, and morphological data for biological characterization of Ryukyus plant species, especially threatened species.

Oxalis amamiana, endemic to Amami Island

Eriachne armittii, endemic to Iriomote Island

Ophiorrhiza yamashitae, endemic to Amami Island (CR)

Aster asa-grayi, endemic to Amami and Okinawa islands (EN)

Shortia rotundifolia distributing in the Ryukyus and Taiwan (NT)

Cassytha pergracilis, endemic to Okinawa Islands (CR)