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Japanese Scientists Discover New Species of Non-blooming Orchids on Japanese Subtropical Islands

The new species named Gastrodia Amamiana was discovered on the subtropical islands of Amami-Oshima and Tokunoshima, this orchid bears fruit without once opening its flowers.

The research team was led by Associate Professor Kenji Suetsugu of the Kobe University Graduate School of Science, in collaboration with Amami-Oshima residents and independent scientists Hidekazu Morita, Yohei Tashiro, Chiyoko Hara and Kazuki Yamamuro.

Certain plants do not photosynthesise and have evolved to be parasites, feeding off the hyphae of host fungi. These plants are known as mycoheterotrophs. They only show themselves above ground for brief periods when fruiting or in flower. This makes it difficult to find and classify them, and their true identify remain a mystery. Professor Suetsugu and his colleagues are working to document these mysterious mycoheterotrophs in Japan.

Upon further analysis of Gastrodia Amamiana, they discovered that although it resembles Gastrodia uraiensis there are differences in the structure of its petals and column. Interestingly, Gastrodia Amamiana self-fertilizes in bud form without opening its flowers. Non-photosynthesizing plants often grow on the dark forest floor, an environment rarely visited by pollinators like bees and butterflies.

Mycoheterotrophs are parasitic lifeforms, so only stable ecosystems with resources to spare can support multiple mycoheterotrophs species. The discovery of different mycoheterotrophic species in these forests is evidence of a rich habitat beneath the forest floor, including a fungal network hidden from plain sight.

However, many of these natural habitats are becoming potential locations for logging. Tree-thinning was taking place near the discovery location of Gastrodia Amamiana, and the resulting dry soil may negatively impact the habitat by drying out the fungi.

“These field surveys rely on cooperation from independent scientists, and our resources are limited, meaning that some species may reach extinction without ever being discovered by humans,” Professor Suetsugu comments. “The discovery of G. amamiana highlights the importance of the forests of Amami-Oshima. We hope that revealing these new species will draw more attention to the environmental threat faced by these regions.” [APBN]

Source: Suetsugu. K (2019). Gastrodia amamiana (Orchidaceae; Epidendroideae; Gastrodieae), a new completely cleistogamous species from Japan. Phytotaxa 413 (3): 225–230 doi: http://dx.doi.org/10.11646/phytotaxa.413.3.3