image: (A) Inflorescence. (B) Close up of inflorescence. (C) Flower. Scale bars: 10 mm (A & B) and 5 mm (C). view more
It is extremely rare for a new plant species to be discovered in Japan, a nation where flora has been extensively studied and documented. Nevertheless, Professor SUETSUGU Kenji and his associates recently uncovered a stunning new species of orchid whose rosy pink petals bear a striking resemblance to glasswork (Fig. 1). Since it was initially spotted near Hachijo Island in Tokyo Prefecture, the new species has been given the name Spiranthes hachijoensis. Interestingly, it can be found in familiar environments such as lawns and parks, and even in private gardens and on balconies. This research suggests that other new species may be hiding in common places, eliminating the need to venture into remote tropical rainforests to discover them.
The genus Spiranthes encompasses a captivating and gorgeous variety of orchids, which exhibit an array of distinctive morphological traits. The flowers are typically small and white or pinkish, and arranged in a spiral around a central stalk, hence the moniker "ladies' tresses." Spiranthes is the most familiar orchid in Japan and has been cherished for centuries, even appearing in the Manyoshu, Japan’s oldest extant anthology of poetry. For a long time, it was believed that the Spiranthes on the Japanese mainland constituted a single species: Spiranthes australis. However, while conducting extensive field surveys focused on Japanese Spiranthes specimens, Suetsugu came across several populations of an unknown Spiranthes taxon with hairless flower stems, on the mainland of Japan (Fig. 1). The unknown taxon often grows alongside S. australis but blooms about a month earlier, thus leading to reproductive isolation between the two taxa. Given that 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 precisely how these plants differed. Specimens were collected from various locations in Japan, Taiwan, and Laos.