An elegant new orchid is hiding in plain sight

It is extremely rare to discover a new species of plant in Japan, a nation where the flora has been extensively studied and documented. However, Professor Suetsugu Kenji and his colleagues have recently discovered a surprising new species of orchid, whose rose-pink petals bear a striking resemblance to glasswork.

Since it was originally identified near Hachijo Island in Tokyo Prefecture, the new species was named Spiranthes hachijoensis. Interestingly, it can be found in familiar environments such as lawns and parks, and even in private gardens and balconies. This research suggests that other new species may be hiding in common places, eliminating the need to venture into remote rainforests to discover them.

The paper was published online at Journal of Plant Research on March 17, 2023.

The genus Spiranthes includes a fascinating and beautiful variety of orchids, which exhibit a number of distinctive morphological features. The flowers are typically small and white or pink, and arranged in a spiral around a central stem, hence the name “lady’s tress”. Spiranthes is the most familiar orchid in Japan and has been worshiped for centuries, even appearing in the Manyoshu, Japan’s oldest surviving anthology of poetry.

For a long time, Spiranthes in mainland Japan were thought to be a single species: Spiranthes australis. However, while conducting extensive field research focusing on specimens of Japanese Spiranthes, Suetsugu encountered several populations of an unknown Spiranthes taxon with glabrous flower stems in mainland Japan.

The unknown taxon often grows alongside S. australis but flowers about a month earlier, thus leading to reproductive isolation between the two taxa. Since S. australis is characterized by a hairy flower stem, the hairless individuals may represent an overlooked species. Consequently, Suetsugu and his colleagues embarked on a comprehensive and multifaceted ten-year study to determine exactly how these plants differ. Samples were collected from various locations in Japan, Taiwan and Laos.

By integrating results from DNA analysis, morphology, field observations, and reproductive biology, Suetsugu and colleagues discovered that it is a cryptic species that exhibits a high level of molecular divergence, albeit with little morphological variation. The fact that the “common” Spyranthi is indeed divided into two species is likely to pique the curiosity of the general public.

The discovery of a new species of flowering plant in Japan is considered an extremely rare event since the flora of this region has been extensively researched. However, the new species listed here can be found growing even in commonplace environments such as parks and lawns. Some specimens used to describe this new species were collected from private gardens and balconies. This discovery of new species hiding in common locations highlights the need for persistent exploration, even in seemingly unusual environments.

This research was conducted by a multi-institutional team of researchers, including Professor Suetsugu (Graduate School of Science, Kobe University), Professor Suyama Yoshihisa (Graduate School of Agricultural Science, Tohoku University), and Dr. Tian-Chuan Hsu (Taiwan Forestry Research Institute).